# Safetygram

# NCI-Frederick 

ISM-148 GENERAL APRIL 2003

**HEAT STRESS**

The effects of heat stress can range from transient heat fatigue to
serious illness and even to death. Heat stress is caused by a number of
interacting factors, including environmental conditions (such as high
temperatures and/or high humidity), clothing, workload, and the
individual characteristics of the worker. A previous heat injury
(including sunburn) can also affect an individual's susceptibility to
further heat injury. Workers who have suffered a previous heat injury,
or who have sunburn, must be especially vigilant in preventing heat
strain and injury.

Overexposure to ultraviolet (UV) radiation may damage the skin and cause
sunburn. Sunburn increases an individual's susceptibility to other forms
of heat stress. Any worker with sunburn must pay extra attention to the
prevention of heat cramps, heat exhaustion, and/or heat stroke. Chronic
exposure to sunlight, especially the UV-B component, accelerates skin
aging and increases the risk of skin cancer. Fair-skinned individuals
are very prone to this effect; however, increased skin pigmentation
reduces the skin sensitivity by as much as a factor of 10.

**Heat Injury Prevention**

These are a few guidelines you should follow in trying to prevent heat
strain:

-   Stay in good physical condition.

-   Follow an appropriate work-rest schedule.

-   Drink plenty of liquids, including electrolyte drinks, when
    necessary. In addition, avoid alcohol the night before working in a
    suspected hot environment and avoid caffeinated beverages during the
    workshift.

-   Avoid heavy foods prior to and during work shifts. Heavy foods,
    especially in large quantities, tax the body's cooling system.

-   Wear lightweight, light colored clothing when working in the sun.

-   Take advantage of fans and air-conditioners when available.

-   Get the recommended 8 hours of sleep at night.

-   Allow the body to acclimate to warm environments before starting
    work involving physical activity. Do not begin work with extremely
    demanding activities.

-   Remove impermeable garments during rest periods.

-   All breaks should be taken in a protected rest area out of direct
    sunlight. A shaded tree would be a good example.

-   Watch other co-workers closely for signs and symptoms of heat
    strain.

-   Some medications may make you more vulnerable to heat stress
    injuries. Contact OHS (x11096) or your doctor if you are taking
    medication and will be working in a hot environment.

-   While working in a hot environment, If you notice that your pulse
    rate is over 100 beats per minute, take an immediate rest break in a
    cool area.

**Sunburn/UV Exposure Prevention**

When possible, the following methods should be used to avoid
overexposure to UV rays from the sun:

-   Avoid exposure to the sun between 10:00 a.m. and 2:00 p.m.

-   Wear protective clothing that provides the most coverage, consistent
    with the job to be performed.

-   Protect eyes during sun exposure with UV-absorbing sunglasses or
    tinted safety glasses.

-   Use a commercial sunscreen, preferably with a skin protection factor
    (SPF) of 15 or greater. Sunscreen should be applied 15 to 30 minutes
    before exposure to the sun and reapplied every 60 to 90 minutes. It
    is best to use a sunscreen that claims to protect against both UV-B
    and UV-A rays.

-   If sunburn occurs, apply cool compress to area. Also apply aloe vera
    lotion to sunburned area.

**Heat Injury Treatment**

The following are general guidelines to be followed for heat stress
treatment. For explanations of heat strain injuries and their
treatments, refer to Table 1 on the following page.

-   Eat foods that contain salt and consume salted drinking H~2~O;

-   Remove worker to cool shaded area for rest;

-   Loosen clothing and remove PPE;

-   Lay worker down with head low;

-   Apply cool compress to individuals face, to help bring body temp
    under 38°C. (100.4F°)

-   Provide cool fluids (one cup of water every 20 minutes); and

-   Monitor vital signs and seek medical help, if vital signs worsen.

EHS utilizes the Metrologger by Metrosonics hs.3700 Heat Stress Data
Logger. Heat stress values are calculated using the same equations:

WB=Wet Bulb Globe Temperature Index

NWB=Natural Wet-Bulb Temperature

DB=Dry-Bulb Temperature

GT=Globe Temperature

1.  Outdoors with solar load:

> WBGT=0.7NWB+0.2GT+0.1DB

2.  Indoors or outdoors with no solar load:

> WBGT=0.7NWB+0.3GT

**Table 1: Heat Injuries and Illnesses**

+------------+------------+----------------+---------------------------+
| **Heat     | **Cause**  | **Si           | **Treatment**             |
| Injury     |            | gns/Symptoms** |                           |
| /Illness** |            |                |                           |
+------------+------------+----------------+---------------------------+
| **Heat     | -   **Skin | -   **Skin     | **Move worker to a cool   |
| rash or    |            |     rash**     | shaded area.**            |
| prickly**  |    remains |                |                           |
|            |     moist  | ```{=html}     | **If possible, the        |
|            |     for    | <!-- -->       | affected individual       |
|            |     long   | ```            | should take a shower, dry |
|            |            | -   **Tingling | skin thoroughly, and      |
|            |    periods |     or         | change undergarments as   |
|            |     of     |     prickling  | needed.**                 |
|            |     time** |                |                           |
|            |            |    sensation** | **Most cases of heat rash |
|            | ```{=html} |                | will disappear when the   |
|            | <!-- -->   |                | affected individual       |
|            | ```        |                | returns to a cool         |
|            | -          |                | environment.**            |
|            |  **Plugged |                |                           |
|            |     sweat  |                |                           |
|            |            |                |                           |
|            |    ducts** |                |                           |
+------------+------------+----------------+---------------------------+
| **Heat     | -          | -   **Muscle   | **Move worker to a cool   |
| c          |    **Heavy |     spasms and | shaded area for rest.**   |
| ramps/heat |            |     pain in    |                           |
| tetany**   | sweating** |     the hands, | **Provide fluid           |
|            |            |     feet, and  | replacement.**            |
|            | ```{=html} |     abdomen**  |                           |
|            | <!-- -->   |                |                           |
|            | ```        |                |                           |
|            | -   **     |                |                           |
|            | Inadequate |                |                           |
|            |     e      |                |                           |
|            | lectrolyte |                |                           |
|            |     (salt) |                |                           |
|            |     rep    |                |                           |
|            | lacement** |                |                           |
+------------+------------+----------------+---------------------------+
| **Heat     | -   **Deh  | -   **Pale,    | **Move worker to a cool   |
| exhau      | ydration** |     cool,      | shaded area for rest.**   |
| stion/heat |            |     moist      |                           |
| fatigue**  | ```{=html} |     skin**     | **Provide fluid           |
|            | <!-- -->   |                | replacement.**            |
|            | ```        | ```{=html}     |                           |
|            | -   **     | <!-- -->       |                           |
|            | Inadequate | ```            |                           |
|            |     blood  | -   **Heavy    |                           |
|            |     cir    |     sweating** |                           |
|            | culation** |                |                           |
|            |            | ```{=html}     |                           |
|            | ```{=html} | <!-- -->       |                           |
|            | <!-- -->   | ```            |                           |
|            | ```        | -              |                           |
|            | -          |   **Dizziness, |                           |
|            |   **Stress |     nausea**   |                           |
|            |     on     |                |                           |
|            |     body   | ```{=html}     |                           |
|            |            | <!-- -->       |                           |
|            |   organs** | ```            |                           |
|            |            | -              |                           |
|            |            |   **Fainting** |                           |
+------------+------------+----------------+---------------------------+
| **Heat     | -          | -   **Hot, dry | **If a worker shows signs |
| Stroke**   |  **Failure |     skin**     | of possible heat stroke,  |
|            |     of     |                | call 911 immediately.**   |
| **(Serious |            | ```{=html}     |                           |
| Medical    | body****s | <!-- -->       | **Place worker in a cool  |
| Em         |     t      | ```            | shaded area and remove    |
| ergency)** | emperature | -   **Lack of, | outer clothing.**         |
|            |            |     or         |                           |
|            | regulation |     reduced,   | **Wet the worker**       |
|            |            |                | **skin and, if possible,  |
|            |   system** | perspiration** | increase the air movement |
|            |            |                | around the worker.**      |
|            | ```{=html} | ```{=html}     |                           |
|            | <!-- -->   | <!-- -->       | **Provide fluid           |
|            | ```        | ```            | replacement.**            |
|            | -   **High | -   **Nausea** |                           |
|            |     body   |                |                           |
|            |     tem    | ```{=html}     |                           |
|            | perature** | <!-- -->       |                           |
|            |            | ```            |                           |
|            |            | -              |                           |
|            |            |    **Dizziness |                           |
|            |            |     and        |                           |
|            |            |                |                           |
|            |            |    confusion** |                           |
|            |            |                |                           |
|            |            | ```{=html}     |                           |
|            |            | <!-- -->       |                           |
|            |            | ```            |                           |
|            |            | -   **Strong,  |                           |
|            |            |     rapid      |                           |
|            |            |     pulse      |                           |
|            |            |                |                           |
|            |            |  (initially)** |                           |
|            |            |                |                           |
|            |            | ```{=html}     |                           |
|            |            | <!-- -->       |                           |
|            |            | ```            |                           |
|            |            | -   **Coma**   |                           |
|            |            |                |                           |
|            |            | ```{=html}     |                           |
|            |            | <!-- -->       |                           |
|            |            | ```            |                           |
|            |            | -   **Death**  |                           |
+------------+------------+----------------+---------------------------+