Abstract:
A far infrared (“FIR”) sauna cabin equipped with a far infrared (“FIR”) heating elements constructed of ceramic, carbon, and/or light emitting diodes (“LED”), designed for therapeutic use in a sauna, capable of emitting far infrared energy, and heating an individual&#39;s skin for purposes of rejuvenation, anti-aging, weight loss, and acne therapy. The FIR heating element emits IR energy in a wavelength and frequency optimum for resonant absorption by the human body, resulting in the release of toxins stored within subcutaneous fatty deposits, which are then carried out of the person&#39;s system as he or she sweats. The FIR sauna cabin is further equipped with necessary hardware and tools to effectively create a more flexible environment in which the user can change seating configurations, move about more freely and conduct stretching routines or exercises within the sauna cabin, using specialized fittings integrated to the interior of the sauna cabin.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/666,839 entitled “FAR INFRARED SAUNA HAVING A PORTABLE SEATING DEVICE, A HEATED LED PANEL, AND AN EXERCISE SYSTEM”, filed Jun. 30, 2012, and U.S. Provisional Patent Application Ser. No. 61/804,284 entitled “SAUNA HAVING A FAR INFRARED HEATING ELEMENTS, A HEATED PANEL, PORTABLE SEATING DEVICE, AND AN EXERCISE SYSTEM”, filed Mar. 22, 2013. 
    
    
     BACKGROUND OF THE INVENTION 
     Sauna heater technology has advanced far beyond the old-fashioned hot rock era. The health benefits of saunas have been recognized for centuries, beginning with ancient Roman baths, to sweat lodges, and other primitive systems that evolved into the well-known traditional hot rock saunas and have culminated in the far infrared (“FIR”) saunas one finds in the market today. All are based on the idea that heating the body and producing perspiration cleanses the cells and pores by removing unwanted substances, such as toxins and acids in the process. Typically, a heat source using wood, electric, or gas is used to produce the heat in a sauna. The old-fashioned hot rock saunas require extreme, and often, unsafe heat, which warms the room, the walls, and the entire sauna environment prior to transferring any significant heat to the individual seated within the sauna. In addition, once constructed in place, traditional electric heating elements in hot rock saunas have considerable power requirements and are often nearly impossible to move to a different location. 
     Thus, in recent years, far infrared technology has been used to replace the traditional hot rock saunas. Infrared (“IR”) energy, or radiant heat, is commonly regarded as that electromagnetic energy with a wavelength between 0.75-1,000 microns (“μm”) on the electromagnetic spectrum, bordering on the visible light spectrum. Far infrared light is usually regarded as being found in the range of wavelengths from 5.6-1000 μm, the longer wavelengths of the IR spectrum while “near” IR and “mid” IR fall in the realm of wavelengths shorter than 5.6 μm, and “nearer” the visible light spectrum with respect to frequency and wavelength. The terms “near,” “mid,” and “far” as applied to IR energy, all refer to their proximity to the visible light spectrum. All infrared light falls outside the visible spectrum, thus is not visible to the human eye. IR energy, or IR radiation as it is often known, including FIR, is perceptible as heat, like the warming rays of the sun. Infrared saunas use this infrared radiation, to heat the body directly, rather than heating the air, and the entire environment around the body, such as a hot rock sauna does. 
     IR energy, and more specifically, far infrared rays, unlike UV radiation, x-rays, or atomic radiation, are safe and often beneficial. When FIR energy hits the skin it transfers heat energy, which penetrates more than an inch and a half into the body to heal and stimulate tissues, making FIR an effective therapeutic tool for arthritis and tissue injuries among other ailments and conditions. In addition, this heating causes the individual to sweat, thus achieving health benefits similar to those from a traditional rock sauna heating techniques. 
     Studies indicate that the use of a far infrared sauna using the correct frequency of infrared rays triggers a process called “resonant absorption” wherein toxins are removed from the cells in our bodies at a higher rate than achieved by high ambient temperatures alone. When comparing far infrared saunas to traditional hot rock saunas, FIR has several other advantages as well. One of the most important differences between traditional hot rock saunas and FIR saunas is the infrared energy enables the IR heating elements to function at a lower surface temperature. Traditional hot rock saunas typically operate at temperatures ranging from 180° F. to 190° F. This high heat can be uncomfortable or even dangerous for some people, especially those with cardiovascular or respiratory problems and can limit the time one can spend in the sauna. This, in turn, limits the amount of sweat that can be produced due to an individual&#39;s tolerance of the environment, reducing the amount of therapy obtainable. The heavy, thick air can be difficult to breathe and evaporation can dry out membranes in the nose and eyes, furthering discomfort. 
     A FIR sauna, on the other hand, typically functions between 100° F. and 140° F., wherein it is estimated that less than 20 percent of the infrared energy generated by the heater goes into the air. Thus, not only does the body receive the other 80 percent of the heat directly, including all of its benefits, many individuals find that the air is more breathable, and apart from the FIR heating elements, there are no hot surfaces. 
     A further benefit of FIR saunas is that an infrared sauna heater uses considerably less electricity than traditional hot rock saunas that use electricity as the power source. The infrared sauna is usually ready to use within 15 to 30 minutes, whereas a traditional rock sauna (depending on their size) can take over an hour to reach optimum temperature. Moreover, many infrared saunas come in kit form and are easier to assemble, so they can be moved to a new location with relative ease, in contrast to the larger and more complicated hot rock saunas. 
     A central principle to the infrared sauna technology is emissivity. Emissivity is a dimensionless measurement of the relative ability of an object&#39;s surface to emit energy by radiation. Typically, the duller and darker an object, the greater its emissivity becomes. Emissivity can have a value from zero (0), as in the case of a shiny mirror that absorbs and radiates no energy, to 1.0, a theoretical maximum, described by a perfect “black body” in thermal equilibrium. The theory states a black body emits as much or more energy at every frequency than any other body at the same temperature. Real materials actually emit energy at a fraction of that of a black body; that is, real materials have emissivity values of less than 1.0. Some ceramics however, have exceptional emissivity values as high as 0.95. 
     Emissivity is further implicated by the way the human body radiates and absorbs heat energy, and thus IR/FIR energy. The average human body radiates and absorbs infrared energy through the skin at wavelengths of 3-50 μm with a concentration of that energy output at 9.4 μm. The goal of FIR heaters is to closely match the wavelength, and thus emissivity, thereby maximizing the rate at which the human body absorbs the IR/FIR energy, or heat. This results in more efficient, faster, and deeper absorption of radiated energy by the human body. In order to achieve this end, the heaters must be carefully designed to produce sufficient amounts of FIR energy within the appropriate band of wavelengths and frequencies. 
     Currently, the three (3) most common materials used in infrared heaters are ceramic, carbon, and infrared light-emitting diodes (LED). Ceramic is a very efficient and effective material when heated to produce infrared energy. Ceramic has a very high emissivity rating, thus it emits, or produces significant infrared heat. The drawback to ceramic heaters is that they tend to produce a shorter wavelength infrared energy than optimum for an FIR sauna application. This is troublesome because the human body does not as easily absorb shorter infrared wavelengths as it does longer FIR wavelengths. This renders sauna heaters that use only ceramic heating elements (and thus shorter wavelengths) less therapeutic. 
     In contrast, carbon infrared heaters produce a longer infrared wavelength. Carbon is very lightweight so the heaters can be bigger and can operate at a lower surface temperature. The lower surface temperatures of carbon heating elements produce longer wave infrared energy, resulting in radiated heat in the FIR spectrum. This heat is more readily absorbed by the human body and will produce results that are more desirable. The drawback of carbon heaters is that while they produce high quality FIR heat in the desired wavelength range, they do not commonly produce a significant amount of the energy, placing them lower on the emissivity curve than a ceramic heater alone. 
     The IR sauna market currently has a number of carbon-ceramic heaters available, however, the majority of these heaters emit the majority of their FIR energy between 0-7 μm, below the optimum, and 9.4 μm FIR energy the human body most efficiently absorbs. 
     Finally, LEDs provide still another option that has proven effective for IR energy production. While the wavelengths of IR energy emitted by IR LEDs are different from carbon and ceramic, their light weight and power output make them a viable alternative and useful as a heating FIR element. While an individual LED provides limited FIR output, many LEDs may be combined to form an array, creating a panel with similar characteristics to the carbon and ceramic panels discussed above. They may be further formed into smaller, portable or customizable sizes with the option of flexible mounting options for use in conjunction with, or independently from, the fixed carbon-ceramic heating elements. 
     Many people seeking the therapeutic benefits of infrared therapy can pay up to thousands of dollars per year for access to FIR saunas in health clubs, paying by session in spas around the country. The present invention will allow users to receive the benefit of both FIR sauna therapy and the LED therapy in the privacy of their own home. 
     The present invention incorporates multiple carbon and ceramic infrared panels mounted to or within the walls of the sauna cabin, in addition to one or more smaller IR LED arrays positioned to optimally transfer FIR energy to the individual sitting within the sauna. The walls and ceiling of the sauna cabin may all include such FIR-emitting panels. 
     A further limitation of typical saunas is interior space. Within the typical sauna, the interior is commonly outfitted with bench-style seating, allowing the user to comfortably enjoy the benefits of the sauna. The benches are most often constructed of wood, with wood slatted seats, allowing more air circulation between the seated user and the bench. Some larger saunas have multiple tiers of bench seating, allowing the user to take advantage of higher temperatures toward the ceiling and increasing available seating for multiple users. However smaller, personal saunas intended for home use are designed with efficient use of space as a primary concern, so as to minimize the sauna footprint, leaving minimal excess interior space. Moreover, while there is some flexibility in the user&#39;s physical position on the bench while seated, benches are fixed in place, restricting the user&#39;s seating options, further limiting floor space. This also leaves room for little more than simply sitting in place and sweating, as opposed to maximizing time spent with exercise or stretching. 
     Saunas have traditionally been used as a form of relaxation and detoxification. With the lower operating temperatures of an FIR sauna, users are now able to remain inside the sauna for up to or even exceeding one hour in duration. For most, this is a long period of time that might be used in more productive ways, such as an exercise routine. Initiating an exercise program inside a FIR heated sauna stimulates more intense workouts while stimulating even more sweat production. There is clinical evidence that conducting a resistance or anaerobic training session in such an environment is more effective for injury prevention, tissue repair, and recovery than the same workout in a normal gym environment. 
     Thus, by incorporating features into the construction of the FIR sauna cabin that allow the user to engage in physical exercise within the sauna cabin, a user benefits from the extended time spent in the sauna, in addition to the ability to use the time for other activities. 
     In light of the above, it would be advantageous to provide a far infrared heating element for IR saunas that produces the long wave infrared heat of carbon heaters combined with the very high infrared output of ceramic heaters, and the flexibility of LED-based infrared heaters. It would be further advantageous to provide a new technology that uses a combination of carbon, ceramic, and IR LEDs that can produce far infrared heat energy with a majority of that heat of a wavelength at or near the level of the human body&#39;s optimum absorption. It would further be advantageous to provide a sauna with user-configurable interior seating options and workout configurations allowing the user to exercise while simultaneously reaping the benefits of FIR therapy. 
     SUMMARY OF THE INVENTION 
     The present invention contemplates a FIR sauna, and FIR heating element that have been shown to provide a 362% faster heat up (to 120 degrees effective temperature), 462% faster sweating by the user, and 339% more sweat than a conventional sauna. An individual&#39;s use of this system results in improved detoxification of the body, cardio-respiratory benefits, accelerated weight loss, skin rejuvenation, and stress relief, all with anti-aging effects. The FIR sauna of the present invention will work for anyone, regardless of fitness level. The FIR heating element of the present invention makes optimum use of a combination of the high volume of infrared heat energy of a ceramic heating element, longer wavelength IR emissivity characteristics of carbon fiber, and the adaptable nature and flexibility of LEDs. The present invention further incorporates a flexible seating system. Additionally, the present invention has attachment points within the structure of the sauna cabin, such as integral “D” rings, allowing the user to attach exercise bands or machines and to conduct an exercise routine while seated within the sauna. 
     The carbon and ceramic FIR heating element of the present invention incorporates a carbon fiber panel in conjunction with an aluminum backing, and highly emissive ceramic heating element, providing a heat source that emits FIR energy with a wavelength of 7-12 μm. 
     The wavelength of the IR energy created by the carbon and ceramic heating element of the present invention is significant due to the absorption characteristics of the human body. The average human body radiates and absorbs infrared energy through the skin at 3-50 μm with a concentration of that energy output at 9.4 μm. The heating element of the present invention emits FIR energy with the majority of radiated heat output in the FIR band, from 7-14 μm, the output spread evenly around the 9.4 μm pivot point of peak human output. This results in more efficient, faster, and deeper absorption of radiated energy by the human body. This distribution maximizes the higher degree of penetration by the FIR waves that produce resonant absorption within human tissue, melting subcutaneous fatty deposits and releasing the toxins stored therein. 
     The deeper penetration and more efficient absorption of the FIR energy and heat by the human body produces a much heavier sweat than hot rocks saunas, steam saunas, and exercise. FIR saunas expose the human body to enough directed FIR energy to melt fat and draw out toxins stored subcutaneously. The toxins are then carried out of the body as the body sweats, purifying the body. 
     The benefits of using the hybrid carbon-ceramic heating system of the present invention are not limited to the emitted IR energy. The low weight—typically less than one (1) pound—of the carbon panel, and other components such as the ceramic heating element, and surrounding aluminum construction provide the user with a lightweight, versatile solution to an infrared sauna heater. This characteristic allows FIR heaters to have larger surface areas, further allowing them to operate at lower surface temperatures maximizing FIR output and making them significantly simpler to construct and easier to transport than traditional hot rock sauna heaters. If constructed from stainless steel, the shroud becomes slightly heavier, but because stainless steel is more IR-reflective than aluminum, less IR energy is lost. 
     IR LEDs also provide a source for FIR energy that may be employed in conjunction with the carbon and ceramic heating elements. The present invention employs additional IR LED arrays arranged on panels installed within the sauna on flexible or movable mounts. This feature allows the user to move the panel and direct it at a specific area of the body, such as the face or calf, depending on the user&#39;s needs. This allows a user to experience FIR heat from the LED panel directly on their face, or other body part, while simultaneously benefiting from the deep penetrating far infrared energy produced by other heating elements within the sauna itself. This double benefit is significant to users. 
     A further advantage of the present invention is encompassed in the seating options provided. While standard bench seats limit space available within the sauna cabin, the present invention facilitates a solution to this lack of versatility and increases the user&#39;s comfort, by providing more versatile seating solutions. Instead of being limited to a fixed bench seat, the present invention includes a hinged bench seat, allowing the user to lift the seat by way of hinges, fold the bench seat into a vertical position, and attach the folded seat to the back wall inside the sauna. The hinged seat not only allows the user to move the bench seat out of the way, increasing floor space within the sauna, but also allows access to a single, pedestal-style seat that may be stored beneath the bench seat while the bench is in the down position. The single, pedestal-style seat may further be affixed to the floor of the sauna giving the user additional seating options and facilitating the conduct of an exercise routine using the sauna&#39;s integral “D” rings, discussed below. The seating options further provide freedom of movement and convenience for the user when the seat is in use, and easily stores underneath the fold down bench, out of site, when not in use. 
     Still another advantage of the present invention is the plurality of “D” rings” or other similar devices installed within the interior of the sauna allowing the user to exercise while using the FIR sauna. These “D” rings can be used as attachment points for exercise implements such as elastic bands or even small workout machines, while the additional space provided enables a user to move about, stretch, perform exercises, and enjoy more freedom of movement within the confines of a FIR sauna, all while simultaneously benefiting from the deep penetrating FIR heat. 
     To facilitate the incorporation of the “D” rings into the structural design of the sauna cabin and provide a stable and secure mounting point, the walls of the cabin also incorporate an external curvature or arch-shape increasing the structural strength of the cabin. The external curvature provides additional strength by distributing force across the wall, and away from the center of force on the “D” ring, (much like the support provided by an arch) counteracting opposing forces imparted on the interior of the cabin when an individual makes use of the “D” rings during exercise. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The nature, objects, and advantages of the present invention will become more apparent to those skilled in the art after considering the following detailed description in connection with the accompanying drawings, in which like reference numerals designate like parts throughout, and wherein: 
         FIG. 1  is a side, cut away view of the interior of an infrared (IR) sauna cabin, with an individual seated therein, and facing the far infrared heating element of the present invention as installed in a wall of the IR sauna cabin, and absorbing the FIR energy emitted by the far infrared heating element. 
         FIG. 2  is a front plan view of the far infrared heating element of the present invention as installed in a wall of an IR sauna cabin, depicting the slotted front of the carbon panel, and enclosure built around the face of the far infrared heating element; 
         FIG. 3  is a perspective view of the front of the far infrared heating element of the present invention depicting the carbon panel, slotted openings in the carbon panel, shrouded metal enclosure, and power supply cords; 
         FIG. 4  is a front view of the ceramic heating element prior to installation in the FIR heating element of the present invention, depicting the power cords and mounting surfaces; 
         FIG. 5  is a front view of the FIR heating element of the present invention with the carbon panel removed, depicting the ceramic heating element, and its position within the metal shroud and power supply cords for the ceramic heating element; 
         FIG. 6  is the back view of the carbon panel, as removed from the FIR heating element of the present invention, depicting the position of the heating layer, the backing on the carbon panel, heating layer, the associated slots in the carbon panel, and the electrical connections thereon; 
         FIG. 7  is a close up view of one of the electrical connections on back of the carbon panel of the present invention depicting the backing, the heating layer, and the cutout in the aluminum backing that accommodates the electrical connection to the back of the carbon panel; 
         FIG. 8  is the back view of an alternate embodiment of the carbon panel without slotted openings, as removed from the FIR heating element of the present invention, depicting the backing (in dashed lines), the position of the electrical connections, and the electrical current bus that distributes current to the carbon heating layers; 
         FIG. 9  is a close up view of one of the electrical connections on the back of the alternate embodiment of the carbon panel of  FIG. 8 , depicting the backing, electrical current bus, and the cutout in the backing that accommodates the electrical connection to the back of the current bus and carbon panel; 
         FIG. 10  is a cross section of the carbon panel, showing the insulation layers on both sides of the carbon panel, the heating layer, the electrical current bus, and the aluminum backing; 
         FIG. 11  is an exploded perspective view of the various layers of the carbon panel of  FIG. 8 , showing the interaction of the two insulation layers on both sides of the heating layer, the electrical connection to the current bus, and the backing; 
         FIG. 12  is another alternate embodiment of the FIR heating element of the present invention, depicting a larger carbon panel having three heating layers, and four ceramic heating elements, spaced peripherally around the four sides of the carbon panel, with associated metal shrouds and electrical connections. 
         FIG. 13  is a perspective view of the back wall of a sauna cabin, to which the base plate of the LED panel assembly is attached, showing power adapter on the back wall, next to the base, LED panel extended away from the sauna wall; 
         FIG. 14  is an alternative perspective view of the LED panel assembly, showing the LED panel, LED array, extension arms, control unit, power supply, and base plate that mounts to the back wall of the sauna cabin; 
         FIG. 15  is a cut away of the inside of a sauna cabin, showing a FIR heating element installed on the back wall, a bench seat attached with hinges to an adjacent wall, and the seat base plate of the pedestal seat assembly installed in the floor of the sauna cabin; 
         FIG. 16  shows the inside of a sauna cabin, depicting the bench seat stowed against the wall allowing installation of the pedestal seat assembly in the seat base plate in the sauna floor; 
         FIG. 17  is a bottom view of the pedestal seat assembly, showing the seat base plate, seat base pole, and seat, further showing the interconnection of the seat base pole and the pedestal seat using a hinge assembly and snap lock; 
         FIG. 18  is a front perspective close up view of the seat pole inserted into the base plate, where the base plate is installed flush with the sauna floor and a hole in the floor to accommodate the barrel mounted to the bottom of the base plate; 
         FIG. 19  is a rear bottom view of the pedestal seat showing the base plate, seat pole, hinge assembly, height control lever, and seat; 
         FIG. 20  is a close up view of the snap locking mechanism engaged to keep the hinge in the closed position. Also shown is the release tab that pulls the locking pin back from the base plate thereby allowing the hinge assembly to open; 
         FIG. 21  is a top view of the hinge in operation, as the snap lock is released, and the seat is rotated away from the hinge base and seat base pole; 
         FIG. 22  is a perspective, cut away view of the interior of a sauna cabin back wall, side wall, floor, showing the slotted front of the carbon panel with the enclosure built around the face of the FIR heating element. Also shown is the “D” ring assembly installed in multiple locations in each panel of the interior of the sauna cabin; 
         FIG. 23  is a plan view of the front of the FIR heating element of the present invention depicting the “D” rings where exercise bands would clip or snap on; 
         FIG. 24  is an exploded view of a preferred embodiment of the “D” ring assembly, showing the mounting hardware, “D” ring, and protective grommet; 
         FIG. 25  is a cross sectional view of the construction of a preferred embodiment of the externally curved sauna cabin wall, showing the interaction of the “D” rings as installed in addition to the forces acting on the curved outer sauna walls. 
     
    
    
     DETAILED DESCRIPTION 
     Referring initially to  FIG. 1 , a cut away view of an exemplary IR sauna cabin, generally labeled  101 , is depicted showing an individual  103  seated therein. The far infrared (“FIR”) heating element of the present invention, generally labeled  100 , is shown installed in wall  102  of sauna cabin  101 . The FIR heating element  100  is shown radiating combined FIR energy  105  in order to heat the individual  103  and cause individual  103  to sweat, providing therapeutic benefits, such as resonant absorption of the FIR energy  105  within individual&#39;s  103  bodily tissues. 
     Referring now to  FIG. 2 , FIR heating element  100  is depicted, installed in a sauna wall  102 . The FIR heating element  100  of the present invention is contemplated herein as a sauna heater, thus it is shown installed in a wooden enclosure  104 , however it should be appreciated by those skilled in the art, that the FIR heating element  100  may be used for other purposes or installed in a variety of other enclosures, such as metal or composite materials. 
     Referring now to  FIG. 3 , the FIR heating element  100  is shown prior to installation in a sauna. A metal shroud  106  provides structural support and mounting points for the ceramic heating element  108  (shown in  FIG. 4 ) and carbon panel  110 . Metal shroud  106  further provides mounting points to allow the entire FIR heating element  100  to be mounted in place or on the sauna wall  102  (shown if  FIG. 2 ). Electrical cables  112  provide electrical power to FIR heating element  100 , and more specifically electrical power individually to ceramic heating element  108  and carbon panel  110 . The power applied is distributed to the carbon panel  110  either directly (described in conjunction with  FIGS. 6 and 7 ), or by use of an electrical current bus (described in conjunction with  FIGS. 8 and 9 ). 
     It is to be appreciated by those skilled in the art that metal shroud  106  may be constructed from various metallic or other IR-reflective materials known in the art. A purpose of metal shroud  106  is to reflect IR energy in the direction of individual  103 . Various types of steel, aluminum, or alloys are suitable for this type of application. Metal shroud  106  may also take many different shapes and sizes, varying the reflective properties and direction of reflected energy. 
       FIG. 3  depicts a plurality of slots  116  formed within the carbon panel  110 . This Figure shows 16 slots  116  for illustrative purposes. The number of slots may vary with the size of carbon panel  110 , desired output of the FIR heating element  100 , and application thereof. In other words, the number of slots  116  depicted should not be viewed by those skilled in the art as a limiting characteristic of the present invention. More specifically, slots  116  are implemented to allow a greater volume of the IR energy produced by the ceramic heating element  108  to flow through the carbon panel  110  in order to reach the individual  103  inside the sauna cabin  101 . The number of slots  116  described herein is therefore fully adaptable to create a specific IR energy output while maximizing the desired FIR energy  105  output. 
     Referring now to  FIG. 4 , the ceramic heating element  108  is depicted, as it would be found prior to installation in FIR heating element  100 . The ceramic heating element  108  used in the construction of FIR heating element  100  may be one of the many varieties of ceramic heating elements commercially available in the market. This Figure shows the cylindrical nature of the ceramic heating element  108 , in addition to its mounting points  109 . When power is applied via electrical supply  112  across the ceramic heating element  108 , the impedance of ceramic heating element  108  causes a transfer of energy resulting in ceramic heating element  108  heating up. As ceramic heating element  108  increases in temperature, it begins radiating IR energy. This radiation flows radially away from ceramic heating element through slots  116  in carbon panel  110  to the individual  103  inside the sauna cabin  101 . IR energy  107  flowing toward metal shroud  106  is reflected, so this energy also flows through slots  116 . The IR energy emitted by ceramic heating element  108  combines with FIR energy  105  emitted by carbon panel  110  to provide individual  103  with combined FIR energy  105 , as shown in  FIG. 1 . 
     Referring now to  FIG. 5 , ceramic heating element  108  is installed in metal shroud  106 . The interior shape of metal shroud  106  is optimally designed to reflect the IR energy  107  away from the FIR heating element  100  and direct the IR energy  107  toward the individual  103  inside the sauna cabin  101 . It is to be appreciated by those skilled in the art that the shape of metal shroud  106  is variable based on application. In the present embodiment, metal shroud  106  and ceramic heating element  108  are placed behind carbon panel  110  in an effort to minimize the overall size of the FIR heating element  100 . As will be explained in additional embodiments, ceramic heating element  108  may be placed alongside carbon panel  110 , or multiple ceramic heating elements  108  may be employed to increase the volume or modify the direction of IR energy  107  emitted. 
     Referring to  FIG. 6 , the reverse side of the carbon panel  110  is shown. This Figure depicts aluminum backing  118  (shown in dashed lines) adhered to carbon panel  110 , slots  116  formed in the panel  110 , electrical connections  120  and  121 , and heating layer  130 . The focus of this figure is electrical connections  120  and  121 . Electrical cables  112  provide electrical power to the ceramic heating element  108 , and to electrical connections  120  and  121 . Electrical connections  120  and  121  are affixed to the back of carbon panel  110 , and create an electric potential across carbon panel  110 , transferring an electrical charge to the heating layer  130  within carbon panel  110  when energized. The electric potential creates an electric current through heating layer  130  of the carbon panel  110 . Heating layer  130  is composed of carbon fiber. Since metals, such as aluminum, conduct more heat than carbon fiber, the aluminum backing  118  is fit in place to assist in distributing the heat across carbon panel  110 . Such an arrangement more evenly distributes the heat produced by carbon panel  110  and more efficiently heats carbon panel to an appropriate temperature. Carbon panel  110  then increases to approximately 100°-140° F. and emits IR energy  107  in the desired FIR band. 
     As carbon panel  110  increases in temperature and begins to emit FIR energy  105 , the FIR energy  105  is radiated in all directions. Aluminum backing  118  further serves to direct (and reflect) FIR energy  105  emitted by carbon panel  110  toward individual  103 . 
       FIG. 7  is a close-up view of electrical connection  120 . In a preferred embodiment, electrical connection  120  is identical to electrical connection  121 , differing only in the polarity of the electrical charge. It should be appreciated by a person skilled in the art that electrical connections  120  and  121  are polarity insensitive. This Figure depicts electrical connection  120  affixed directly to heating layer  130  of carbon panel  110  and aluminum backing  118  as a dashed line. In this embodiment, the electrical potential is applied directly to the carbon material within heating layer  130 . 
     Referring to  FIG. 8 , an alternative embodiment of carbon panel is shown and generally designated  200 . In this embodiment, heating layer  230  is constructed of pulverized carbon or carbon fiber and is the active heating element of carbon panel  200  of the present invention. Once electrified via electrical connections  231  and  232 , heating layer  230  produces the FIR energy  105  desired by the present invention. In order to more efficiently distribute an electrical charge across heating layer  230 , current bus  234  is implemented, providing a direct electrical connection between heating layer  230  and electrical connections  231  and  232  via the pulverized carbon or carbon fiber. 
     Depending on the composition of the carbon in heating layer  130 , electrical connections  120 ,  121 , such as those shown in  FIGS. 6 and 7 , might cause uneven heating of heating layer  130  should the conductive properties of the carbon be inadequate to conduct electricity evenly across heating layer  130 . In that situation, power applied to carbon panel  110  may heat a limited area around electrical connections  120 ,  121  more than the rest of the entire heating layer  130 . This may cause “hot spots” where electrical connections  120 ,  121  are made, in  FIGS. 6 and 7 . The hot spots can burn the carbon in that area of heating layer  130  and result in a shorter operational life for the entire carbon panel  110 . To combat this, carbon panel  200  employs current buses  234  and  236  to provide longer electrical connections to heating layer  230  thereby creating a more even electrical current distribution in heating layer  230 . Electrical connections  231  and  232  connect directly to current buses  236  and  234  respectively, which is in direct electrical contact with heating layer  230  and allows for more effective and efficient transmission and distribution of electrical potential across carbon panel  200 , creating a more even electrical connection across the width of heating layer  230 . 
     In an embodiment, carbon panel  200  utilizes copper current buses  234  and  236  to conduct and distribute the electrical current across heating layer  230 . Copper is known in the art as a particularly conductive material commonly used in electrical wiring and readily availability in the market. This aspect however does not preclude the use of other conductive metals for current buses  234  and  236 , such as aluminum. Current buses  234  and  236 , on either end of heating layer  230 , evenly distribute the electrical charge across both ends of heating layer  230  due to the effectively zero (0) resistance of current busses  234  and  236 , and thus enhances heat distribution across carbon panel  200 . This results in the effective alleviation of the hot spots that could form around electrical connections  231  and  232 . 
     In an embodiment, such as that described by  FIG. 8 , carbon panel  200  has multiple, narrower heating layers  230 , as shown. Due to the limited conductive properties of carbon fiber as discussed, the narrow design is appropriate in some circumstances. The narrower width of heating layers  230  in  FIG. 8  reduces the distance an electrical charge must travel, further reducing the chances of hot spots in heating layers  230 . The number of heating layers  230  selected herein (two) is chosen for illustrative purposes only and is not intended to be limiting. Composition of the carbon and power applied to the system, among other factors, may dictate a different width, number of heating layers  230 , and their shape. 
       FIG. 8  further depicts the position of insulating layers  224 ,  225 ,  226 , and  227 . Insulating layers  224 ,  225 ,  226 , and  227 , more accurately depicted in  FIG. 10 , serve to insulate heating layer  230 , electrical connections  231  and  232 , and current buses  234  and  236  from lost voltage and heat, or other interference. Insulating layers  224 ,  225 ,  226 , and  227  further provide structural support and rigidity for heating layer  230 . In this alternative embodiment, insulating layers  224 ,  225 ,  226 , and  227  are constructed from multiple layers of fiberglass and resin. These layers become translucent when cured and allow for easy transmission of FIR energy  105  when heating layer  230  is energized. Those skilled in the art will appreciate that other materials, apart from fiberglass, may be utilized for this purpose. Urethane, Plexiglas, Lucite, or other non-conductive, heat-resistant materials with similar characteristics may be employed for the same purpose. Fiberglass was chosen for the present embodiment due to its minimal weight, flexibility, and ease of construction; however, this should not be viewed as a limiting aspect of the present invention. In an embodiment, the flexible nature of the fiberglass further allows for installation of carbon panel  200  in a non-linear manner, should a design call for a curve in the shape of carbon panel  110 . 
     Referring to  FIG. 9 , a close up view of the electrical connection  231 , as depicted in  FIG. 8 , is shown. This Figure shows aluminum backing  218  in dashed lines. As installed, heating layer  230  is not visible from the back of carbon panel  200 , as the aluminum backing  218  covers the majority of heating layer  230  and current buses  234  and  236 . 
     Referring now to  FIG. 10 , a cross section of carbon panel  200  is shown. Electrical connection  231  (or  121  of carbon panel  110 ) imparts an electric potential across heating layer  230 . Electrical connection  231  is shown in this Figure in direct contact with current bus  234 , and is shown in dashed lines where it passes through insulating layers  224  and  225  as well as aluminum backing  218 . Insulating layers  224 ,  225 ,  226 , and  227  provide a barrier for the electricity imparted by the electrical potential across carbon panel  200 , and more specifically heating layer  230 . 
     Heating layer  230  and current bus  234  are sandwiched between insulating layers  224  and  225  and insulating layers  226  and  227 , where an adhesive, such as epoxy resin, holds them in place. Further, aluminum backing  118  is secured to the back of carbon panel  110  with an adhesive. 
     In an embodiment, other suitable metallic materials are substituted for aluminum and copper in the present invention. Aluminum and copper are readily available in the market and provide suitable electrical performance for the present invention at a reasonable expense; however, other embodiments could utilize other conductive materials for current busses  234  and  236 , such as nickel, gold, silver, or any one of innumerable metal alloys. 
       FIG. 11  depicts an exploded, perspective view of the cross section of carbon panel  200 . In an embodiment, carbon panel  200  has six (6) layers: insulating layers  224 ,  225 ,  226 , and  227 , heating layer  230 , and aluminum backing  218 . Heating layer  230  is sandwiched between them, as shown in this Figure and  FIG. 10 . Current bus  234  is in direct electrical contact with heating layer  230  and electrical connection  231 . This cross sectional view is also representative of carbon panel  110  as in  FIGS. 6 and 7 , except for the sole addition of current bus  234 . 
     The six (6) layers described herein are not intended to be limiting. The thickness of insulating layers  224 ,  225 ,  226 , and  227  may dictate more or fewer layers, in addition to the thickness and conductive properties of the carbon within the heating layer  230 . Moreover, a different material may be substituted for aluminum backing  218  to provide the same functions. 
     Carbon Panel 
     The length of the carbon fibers that make up heating layer  130  is significant. Carbon fibers themselves are approximately 5 μm-10 μm thick and the narrow dimensions of the fibers determine the ultimate FIR energy  105  output of the entire carbon panel  200  (or carbon panel  110 ). As the heating layer  230  increases in temperature, due to inherent qualities and emissivity, the carbon fibers within heating layer  230  emit radiation, ideally in the FIR spectrum. The fibers themselves, as well as carbon panel  200  (and heating layers  230 ) may be varied in size, allowing the manufacturer to “tune” the wavelength of the FIR energy  105  and amount of energy that is radiated therefrom, in order to achieve the precise 9.4 μm desired for optimum resonant absorption by the human body. 
     In an embodiment, the carbon material comprising the heating layer  130  or  230  is doped with additional compounds, such as semi-conductor compounds, that may further “tune” the FIR energy  105  output. Since the surface temperature of carbon panel  200  has a direct effect on the FIR energy  105  output of FIR heating element  200 , a modified carbon compound within heating layer  230  that adjusts conductivity of the carbon will directly affect the surface temperature of carbon panel  200 , and thus the FIR energy  105  output of the entire system. 
     Now referring to  FIG. 12 , shown is another alternative embodiment of the FIR heating element of the present invention and generally referred to as  300 . This embodiment includes four ceramic heating elements  108  placed along the four sides of carbon panel  310 , each housed in its own metal shroud  306 . Metal shrouds  306  provide similar function as metal shroud  106  above, reflecting IR energy  107  from the ceramic heating elements  108  in use, toward the individual  103  seated within IR sauna cabin  101 . In this embodiment, ceramic heating elements  108  are not placed behind carbon panel  110 , and therefore like the previous alternate embodiment, slots analogous to slots  116  are not required. This embodiment is designed for larger FIR heating element  300  applications within an IR sauna cabin  101 . 
     In this alternative embodiment, the operation of FIR heating element  300  is ostensibly the same as described above. Electrical power is supplied by electrical cables  312 , to power all four ceramic heating elements  108 , in addition to providing electrical power to electrical connections  320  and  321  (shown in dashed lines) and current buses  334  (shown in dashed lines). Once powered, the electrical potential is present across larger carbon panel  310 , transferring heat. Ceramic heating elements  108  in this alternative embodiment provide IR energy as before, with more combined surface area and approximately four times the output as a single ceramic heating element  108 . In this embodiment, ceramic heaters  108  and carbon panel  310  are electrically connected in a serial configuration. It is to be appreciated by someone skilled in the art that power to ceramic heaters  108  and carbon panel  310  can be by an electrically parallel configuration, an electrically serial configuration, or a combination of parallel and serial configurations, depending on the needs of the actual sauna cabin  101  design and the power requirements of the individual components. 
     Larger carbon panel  310  is shown in  FIG. 12  having three heating layers  330 , however it is to be appreciated that like the previous alternate embodiment, larger carbon panel  310  may be formed with many different variations in the number of smaller heating layers  330  and their orientation with respect to each other and the sauna cabin  101  itself. 
     Located behind heating panels  330  is aluminum backing  318  (shown in dashed lines). The function of aluminum backing  318  is similar to aluminum backing  118  shown in  FIGS. 6 and 7  and aluminum backing  218  in  FIGS. 8-11 . In this embodiment, aluminum backing does not have slots  116  as shown in  FIG. 6  since there is not a ceramic heater located behind the aluminum panel  318  that would require the use of slots to allow IR energy  117  to pass through. 
     In an embodiment, current buses  334  may further be enlarged or lengthened to optimize the voltage and current applied to the heating layer  330 . 
     Referring now to  FIG. 13 , user  103  is seated in the exemplary sauna cabin  101 , depicted with the further addition of LED panel assembly, generally labeled  400 , attached to the back wall  102  of sauna  101 . 
       FIG. 14  shows an isolated view of the LED panel assembly  400 , having an LED panel  402  on an articulated arm system  404  attached to a base  406 , further attached to the interior wall of a sauna cabin  101 . LED array  408  contains a plurality of individual IR LEDs  409 , in quantities that provide sufficient FIR energy  105  for a given application. In a preferred embodiment, LED panel assembly  400  is used in conjunction with multiple FIR heating elements  100  within the same sauna cabin  101 . 
     In a preferred embodiment, due to the use of the arm system  404 , user  103  may pull LED panel  402  toward him or her, and position it such that FIR energy  405  emitted from LED panel  402  is concentrated on a specific area of the user&#39;s  103  body, such as the face. In a preferred embodiment, LED panel  402  is connected to base  406  by a series of two or more extension arms  404   a  and  404   b  that are moveable by way of arm hinge  410  between upper extension arm  404   a  and lower extension are  404   b , and base hinge  412  between lower extension arm  404   b  and base  406 . Arm hinge  410  and base hinge  412  are designed and constructed with sufficient tension such that when user  103  pulls LED panel  402  to the desired position, it remains in place until moved again. 
     In an embodiment, LED array  404  on LED panel  402  has a user-selectable FIR output, controlled by control unit  414  on base  406 . Power to the LED panel assembly  400  is also controlled through control unit  414  and receives power through power adapter  415  and power cord  416  from power receptacle  418  within the sauna cabin  101 . Power is supplied from power receptacle  418  (see  FIG. 13 ) through base  406 , to LED panel  402  from control unit  414 , via electrical conduit (not shown) within extension arms  404   a  and  404   b.    
     In an alternative embodiment, power to LED panel assembly  400  is supplied through power connections (not shown) that base  406  makes with the wall in sauna  101 , removing the requirement for power cord  416  and power receptacle  418 . In this embodiment, electrical contacts on both the interior sauna wall (not shown), and electrical contacts (not shown) on the bottom of base  406  complete the power circuit and provide power to LED panel assembly  400  when connected to the sauna wall  102  in sauna cabin  101 . 
     Referring now to  FIG. 15 , a cut away view of sauna cabin, generally labeled  500 , is shown with a bench seat  502  built onto a back wall  504  via hinges  506  below a plurality FIR heating elements  100 , of different sizes, also installed in the back wall  504  of sauna  500 . Seat base plate  556  of pedestal seat assembly  550  (shown in  FIG. 16 ) is also shown, built into sauna floor  510 . Three (3) FIR heating elements  100  are shown in this Figure, however the depicted sauna configuration in this Figure is not intended to be limiting, as additional FIR heating elements may also be installed in any wall of sauna  500  as required. Additionally, sauna  500  may incorporate one or more LED panel assemblies  400   
     As shown in  FIG. 16 , at the desire of the user  103 , bench seat  502  may be rotated down against back wall  504  via hinges  506 . Bench seat  502  is completely out of the way, providing additional space within the sauna  500 . In use, bench seat  502  may be secured to side walls  508  with the use of horizontal supports  512 . In an alternative embodiment, bench seat  502  is not permanently secured to any of the three walls (back wall  504  and side walls  508 ), but merely rests on horizontal supports  512  and a back wall support (not shown) that is built into back wall  504 . In such an embodiment, the horizontal supports  512  and back wall support (not shown) support the bench seat  502  in use. In this embodiment, the entire bench seat  502  may be lifted off the supports and out of position and stowed vertically against back wall  504  or may be removed from the sauna cabin  500  altogether. 
     In still another alternative embodiment, bench seat  502  may, instead of rotating down, be rotated up to the vertical and secured to the back wall  504 , again moving the bench out of the way. In this alternative embodiment, horizontal supports  512  remain, providing support of either end of bench seat  502  in use, while hinges  506  provide support for bench seat  502  along back wall  504 . 
     Once bench seat  502  is no longer in the way, pedestal seat assembly  550  may be installed in the floor, or more specifically, attached to seat base plate  556  providing a seating solution immediately in front of the FIR heating elements  101 . Pedestal seat assembly  550  provides the user with a more comfortable and adjustable seating option than a fixed bench seat. This aspect should not be considered limiting to those skilled in the art, as any number of installation positions may be selected by the user, based on personal preference. Alternatively, the user  103  may also dispense with installation of pedestal seat assembly  550 , and utilize the additional floor space within the sauna  500  for stretching or other exercises. 
     Referring now to  FIG. 17 , a bottom perspective view of the pedestal seat assembly, generally labeled  550 , is shown, depicting the pedestal seat  552 , seat base pole  554 , seat base plate  556  and associated hardware. Pedestal seat  552  is connected to seat base pole  554  by way of hinge assembly  558 . The hinge assembly&#39;s  558  axis lies on the rear of pedestal seat  552 , allowing pedestal seat  552  to fold backward, decreasing its overall volume and allowing pedestal seat assembly  550  to be stowed in a more compact manner when not in use. Also shown in  FIG. 17  is the snap lock  560 , attached to the bottom of pedestal seat  552 . Snap lock  560  latches to the hinge base  570  (shown in  FIG. 21 ) when pedestal seat assembly  550  is in use. Releasing snap lock  560  allows pedestal seat  552  to be folded backward as described above. 
     In a preferred embodiment, seat base pole  554  is formed with a male end  562  that fits securely into barrel  564  (shown in  FIG. 15 ) in seat base plate  556 , in use. This feature provides a stable platform for the support of pedestal seat assembly  550  and user  103  in use but also allows easy removal and stowage of pedestal seat assembly  550  when not in use. Additionally, the connection between male end  562  and barrel  564  allows the free rotation of the entire pedestal seat assembly  550 , about the male end  562 . Snap lock  560  secures hinge assembly  558  in the closed position, as shown, preventing pedestal seat  552  from folding and user  103  from falling backwards off the pedestal seat  552  when seated. 
     While  FIG. 17  depicts a pedestal seat  552  that has a defined “front” and “rear,” this should not be considered limiting. Alternative embodiments may employ any practical shape, such as a round pedestal seat. 
     In order to accommodate various user  103  statures, the preferred embodiment of pedestal seat assembly  550  incorporates a hydraulic cylinder into the seat base pole  554 , with height control lever  566 , allowing adjustment of seat assembly  550  to various heights. Height control lever  566  is provided to release pressure within the hydraulic cylinder (not shown) to adjust the height of the pedestal seat  552 . When user  103  occupies the seat and actuates the height control lever  556 , user&#39;s  101  bodyweight compresses the cylinder, lowering pedestal seat  552  to the desired height. When user  101  releases height control lever  566 , pedestal seat  552  will remain at the selected height, until adjusted further. If the pedestal seat  552  is not occupied and in a low position, when height control lever  556  is actuated the cylinder will extend, raising the pedestal seat  552 . This system functions identically to common office chair systems in the market, however in a preferred embodiment, the materials used are selected so as to be compatible with the elevated temperature, sometimes humid sauna environment, and the user&#39;s  103  sweat. 
       FIG. 18  shows the interaction between the seat base pole  554  and seat base plate  556  when user  103  inserts male end  562  into barrel  564 . Mounted within the floor  510  of sauna  500  is seat base plate  556  such that the top of the seat base plate  556  is flush with sauna floor  510 . Barrel  564  in seat base plate  556  is sized to accommodate male end  562  of seat base pole  554 . During construction of the sauna  500 , in order to properly install seat base plate  556  in the floor, a hole must first be established in sauna floor  510  to accommodate barrel  564  when seat base plate  556  is installed. 
     It is to be understood by those skilled in the art that this style of interaction between seat base plate  556  with barrel  564  and male end  562  should not be considered as limiting. In an embodiment, the male end  562  is free to swivel within barrel  564 , ultimately allowing the entire pedestal seat assembly  550  to swivel. In an alternative embodiment, the connection between seat base pole  554  and lower hinge plate  568  allows only the pedestal seat  552  to swivel about the seat base pole  554 , as opposed to the entire system. 
     In another alternative embodiment of the pedestal seat assembly  550 , male end  562  is formed with a spring-loaded latch (not shown) that secures male end  562  within barrel  564 , with a manual release (not shown) formed in the seat base pole  554  for separation of the two elements. 
       FIG. 19  shows a rear bottom view of the pedestal seat  552  in addition to interaction between the lower hinge plate  568  of the hinge assembly  558  and the seat base pole  554 , and the height control lever  566 . Also shown is hinge  559  that rotatably connects lower hinge plate  568  to upper hinge plate  569 . 
       FIG. 20  shows a close up view of the snap lock  560 , in the latched position, on the bottom of pedestal seat  552 . In use, latch  570  retains the edge of lower hinge plate  568  and prevents hinge assembly  558  from operating. Snap lock  560  is manipulated by pulling out on tab  572  in direction  576 , which in turn pulls in latch  570  and releases the edge of lower hinge plate  568  allowing pedestal seat  552  to rotate away from seat base pole  554  and lower hinge plate  568 , as depicted in  FIG. 21 . 
     Referring now to  FIG. 21 , hinge assembly  558  is shown in the open position, after snap lock  560  has been actuated, isolated from pedestal seat  552  and the seat base pole  554 . Lower hinge plate  568  is attached to the top of seat base pole  554 , while upper hinge plate  574  is fastened to the bottom of pedestal seat  502  by way of hardware fasteners, such as bolts or screws (not shown). Provisions for four such fasteners on both upper hinge plate  574  and lower hinge plate  568  are depicted in this Figure, however that should not be interpreted as limiting by those skilled in the art. This configuration of pedestal seat assembly  550  allows for the folding of pedestal seat  552  and easier stowage of pedestal seat assembly  550 , such as under the bench seat  502  in sauna  500  in  FIG. 15  and  FIG. 16 . 
     It should be appreciated by those skilled in the art, that any such latch or similar locking mechanism like snap lock  560  may be employed to prevent pedestal seat  552  from rotating and allowing pedestal seat assembly  550  from folding. In an embodiment, hinge assembly  558  incorporates a locking mechanism into the design of the hinge itself, eliminating the requirement for a separate latching mechanism, such as snap lock  560 . 
     Referring now to  FIG. 22 , a cutaway of the interior of an exemplary exercise sauna  600 , showing three FIR heating elements  100  installed in the back wall  604 , similar to  FIG. 15  and  FIG. 16 . In addition to the other features of previous Figures, multiple “D” rings  620  are installed in the back wall  604  and side walls  608 , and sauna floor  610 . Also pictured is seat base plate  556  installed in sauna floor  610 . Further, and similar to previous embodiments, bench seat  502  is also shown in the stowed position against back wall  604 , providing additional space to user  603  within sauna cabin  600 . 
     “D” rings  620  are designed to provide a fixed point to which exercise implements such as elastic bands  630  or other similar exercise implements may be attached for use while user  603  is inside the sauna. In this Figure, user  603  is depicted working out with two elastic bands  630  attached to back wall  604 . In a preferred embodiment, any number of different exercises may be accomplished through resistance training with elastic bands  630 , making use of the various “D” ring  620  positions within sauna  600 . While the user  603  is inside the sauna cabin, he may take advantage of “D” rings  620  and elastic bands  630  through various arm exercises such as a modified bench press, military press, or innumerable shoulder, core, and arm exercises. By using the floor  610  mounted “D” rings  620 , overhead exercises may also be performed, in addition to leg and core exercises. 
     By conducting a workout within the confines of a sauna  600 , user  603  gains the benefit not only of the resistance training, but also the FIR energy  105  he or she absorbs while inside sauna  600 . The physical exertion of a workout plus the FIR energy  105  produces a much heavier sweat benefitting the user  603  significantly more than exercise alone. 
     Also shown in  FIG. 22  is the seat base plate  556 . This Figure is exemplary of the additional room afforded the user  603  when bench  502  is in the stowed position and pedestal seat assembly  550  is removed. The extra space provided allows the user  603  to conduct many variations of exercise or stretching, hot yoga, resistance training, or other such activities. In an alternative preferred embodiment, user  603  may also install pedestal seat assembly  550  (not shown) using it as support or to further vary the exercise possibilities within sauna  600 . “D” rings  620  are shown in several locations on all walls of sauna  600 , indicative of the versatility and varying options for connection and use of elastic exercise bands  630 . 
       FIG. 23  is a close up view of the back wall  604  of sauna  600 . FIR heating element  100  is installed in back wall  604 , and six (6) “D” rings  620  are shown, fastened to back wall  604 , between FIR heating elements  100 . It is to be appreciated by those skilled in the art that the six “D” rings  620  depicted should not be considered limiting and more or fewer may be installed to optimize or customize the interior of sauna  600 . Virtually any number of “D” rings  620  may be installed at the user  603 &#39;s discretion, providing additional exercise options. The same options exist for the side walls  608  and floor  610 . 
     Referring now to  FIG. 24 , an exploded view of the “D” ring fastener  620  is shown. In a preferred embodiment, the “D” ring  620  has a protective grommet  622 , ring  624 , and bracket  626 . Protective grommet  622  is in a position between the wall  604  of sauna  600  and bracket  626 , secured to wall  604  by way of screws, bolts, and any other hardware typical of this type of installation. Protective grommet  622  is intended to provide a surface against which ring bracket  624  rests, and protection against any damage to wall  604  that might otherwise be caused by clips or fasteners attached to the ring  624  during a user&#39;s  603  exercise routine. 
     Ring  624  and bracket  626  are integrated parts, in which ring  624  is capable of rotation along an axis perpendicular to the plane of the bracket  626 . This enables the ring  624  to fold flat against grommet  622  when ring  624  is not in use. “D” ring  620  provides a connection point for elastic bands  630  or other similar exercise implements desired by the user  603 . In a preferred embodiment, the “D” ring  624  is mounted in such a way that the ring  626  will fall flat against the grommet  622  when not in use. 
     Referring now to  FIG. 25 , a top view of a back wall  604  with a “D” ring  620  installed and an elastic exercise band  630  attached to the “D” ring  630 . Due to the curvature of the outer portion  640  of back wall  604 , when a user  603  (not shown) applies a force to elastic exercise band  630  in direction  630 , an equal and opposite force is also applied in direction  634 . The equal and opposite force is then distributed along the curve formed by outer portion of the back wall  604  in direction  636 . Forces  634  such as these are not typical for sauna construction, and as such, certain modifications to the structure are beneficial. A force  634  such as that described above acting perpendicular to flat inner wall portion  638  may tend to flex the wall inward in direction  632 , bowing the wall  604  and potentially causing damage to the structure with time. However in the preferred embodiment of sauna  600  with “D” rings  620  installed, as shown by  FIG. 25 , sauna walls  609  employ a curvature of the outer wall portions, such as outer wall portion  634  of back wall  604 . This external curvature of the outer sauna wall  609  more effectively distributes the forces imparted on the inner wall portion  638  of back wall  604 . Much like an arch distributes the weight of the bridge or building for which it was built, the external curves more evenly distribute force  634  into smaller force components  640  and prevent the inward bowing that would otherwise be experienced without the use of an externally curved sauna wall  609 , using the “D” rings  620  in sauna  600 . In use, externally curved wall  609  may be utilized in place of sauna back wall  604  or side wall  608 , or corresponding features of other, previously describe embodiments. It is to be appreciated by someone skilled in the art that one or more walls may have a curved out portion depending on the design of a spa and the needs of the user. 
     While there have been shown what are presently considered to be preferred embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope and spirit of the invention.