HETA 90-0395-2121 NIOSH INVESTIGATORS:

JUNE 1991 Ruth A. Shults, R.N., M.P.H.

INTERNATIONAL ASSOCIATION Gary P. Noonan, M.P.A.

OF FIRE FIGHTERS (IAFF) Nina Turner, Ph.D.SEDGWICK COUNTY,

KANSAS

 I. SUMMARY

On September 20, 1990, the National Institute for Occupational Safety and Health

(NIOSH) received a request for a Health Hazard Evaluation from the International

Association of Fire Fighters (IAFF) to assess the health and safety practices during a

brush fire on September 6, 1990, in Sedgwick County, Kansas. A 25-year-old firefighter

died of heat stroke at the scene.

During November 13-15, 1990, NIOSH conducted a site visit to Sedgwick County Fire

Department in Wichita, Kansas. The visit included a tour of the fire scene, personal

interviews with 25 firefighters and support personnel, and review of incident reports,

incident command procedures, and other documents.

Upon arriving at the fire scene on September 6, 1990, the firefighter and the captain

advanced separate booster lines and fought the brush fire for approximately one hour. 

Then, the firefighter rested at the engine alone while the captain of the two-man engine

company reported to command. Upon arriving at the command station, the captain

reported that the firefighter was in need of rehabilitation; then the captain entered

rehabilitation. Over the next few hours several individuals mistakenly identified other

firefighters as the downed firefighter and assured his captain that he had rested and was

then reassigned. The firefighter's body was discovered during cleanup operations.

On the basis of the information obtained during this investigation, the NIOSH investigators

concluded that a preventable series of events preceded the firefighter's death. Recommendations

for incident command and safety procedures, as well as medical monitoring, rehabilitation of

firefighters at fire scenes, and rehydration schedules are present in Section VI of this report.

KEYWORDS: SIC 9224 (Fire Protection), Fire Fighters, Firefighters, Heat Stress,

Heat Stroke, Mortality. 

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports
Page 2 - Health Hazard Report No. 90-395

 II. INTRODUCTION

On September 20, 1990, the National Institute for Occupational Safety and Health

(NIOSH) received a request from the International Association of Fire Fighters (IAFF)

to assess the health and safety practices during a brush fire on September 6, 1990, in

Sedgwick County, Kansas. A 25-year-old firefighter died of heat stroke at the scene. 

Prior to the site visit NIOSH representatives from the Hazards Evaluation and Technical

Assistance Branch and the Protective Equipment Section reviewed relevant documents

including after-incident reports, emergency medical service reports, the decedent's

autopsy report, and department policies addressing physical exam schedules, and

physical conditioning requirements.

During November 13-15, 1990, NIOSH made a site visit to the Sedgwick County Fire

Department (SCFD) in Wichita, Kansas. Accompanied by union and fire department

representatives, NIOSH toured the fire scene. Private interviews were conducted with

SCFD firefighters, administrators, and support personnel, volunteer firefighters, and

Emergency Medical Service (EMS) personnel. 

Additional information requested and reviewed included aerial and land photographs

taken the day following the fire, a transcription of the incident dispatch tape, "Standard

Operation Principles and Procedures" policy, plot maps of the housing addition in which

the fire occurred, an itemized list with weights of the deceased firefighter's personal

protective clothing and personal possessions, weather data, and additional narrative

reports from firefighters who were at the scene.

This report summarizes work practices as they affected the health and safety of the

firefighters, including incident command system, safety management, and medical

services; discusses heat stress; and proposes recommendations.

 III. BACKGROUND

 The Sedgwick County Fire Department (SCFD) Fire Suppression Division employs

approximately 80 firefighters, 15 lieutenants, 21 captains, and 3 division chiefs. The

department primarily responds to fires within Sedgwick County that are outside the

Wichita city limits. 

The deceased firefighter was 24 years old when he began working for the SCFD in

December 1989. He was reported to have been in good health and physical condition. 

His pre-employment physical examination recommended employment without

restrictions.

As reported in the SCFD Fire Investigation Summary, at approximately 10:30 a.m., a

Sedgwick County resident ignited a trash pile, containing 
Page 3 - Health Hazard Report No. 90-395

household trash, cans, glass, and aerosol cans, that was located about

30 feet southwest of his prefabricated modular home. The temperature was 95°F and

winds were blowing out of the southwest at 17-28 miles per hour. The fire spread to the

surrounding area. The first SCFD engine was dispatched at 11:42 a.m. and arrived at

the scene at 11:57 a.m. Additional engines, tankers, and personnel were immediately

dispatched. In total, eighteen SCFD units, including four engines, responded to the

alarm. Additionally, nineteen volunteer firefighters from nearby towns assisted.

 

Winds gusted throughout the afternoon at up to 35 miles per hour, and temperatures

remained in the mid-nineties. Fire consumed most of the area behind the residence on

Lot 11, and the majority of Lot 10, igniting many of the junked cars, and spread to

several adjacent properties (Figure 1). None of the homes in the area, nor the vacant

mobile home on Lot 10, sustained fire damage. Firefighters battled the blaze for three

hours before bringing it under control. Cleanup was completed, and the last unit left the

scene at 9:13 P.M.

 IV. DISCUSSION AND FINDINGS

Management of the Fire Incident

Management of Fire Department day-to-day activities is usually vested in a Fire Chief or

other titled person who serves as the commander of the fire suppression forces and their

activities, including the safety of operating firefighters.1

To assist in the management (especially in the operation, coordination, and

effectiveness) of wide-scale fire suppression activities, a system was developed for

controlling personnel, facilities, equipment, and communications. This system is known

as the Incident Command System (ICS).2 A further refinement of the ICS was later

developed by fire service organizations to address all types of emergency incidents and

included performance criteria for the components of a system that addressed specific

safety and health objectives. This has been developed into a nationally recognized

standard known as the Incident Management System (IMS).3 The National Fire

Protection Association has recognized and documented the consequences of operating

without such an Incident Management System, resulting in numerous deaths and injuries

of firefighters.3,4

Safety Management and IMS

In establishing and utilizing IMS, the first priority must be life safety.2,5 The

responsibility for this priority issue is that of the officer in command of the emergency

incident.4,5 The incident commander is responsible for the overall safety of all members

and all activities occurring at the scene. The Fire Chief, however, bears the ultimate

responsibility for the safety and health of all members of the Department.

The IMS encourages the delegation of authority (but not responsibility) for the safety

function at an incident to a firefighter or other competent person, who is specially

trained and knowledgeable in safe emergency operations.2,6 The failure to delegate

causes conflict between the positions of command and safety. IMS guidelines generally

recommend that the command officer, who is responsible for managing the incident on

the strategic level, establish and operate from a stationary command post as soon as
Page 4 - Health Hazard Report No. 90-395

possible after arriving on the scene.5 In contrast, the delegated safety officer must

routinely observe operations at the scene of an incident. This means he must have full

authority to move around the incident scene (fire ground) to observe and control safety

concerns.5 Based on the investigation of the September 6 fire, NIOSH found that there

was no one in authority who was free to assist the firefighters in recognizing, evaluating,

or controlling fire ground hazards.4

Medical Services

Medical services should be provided and staffed by the most highly trained emergency

medical personnel on the scene. At a minimum, these should be Emergency Medical

Technician-A (Basic Life Support) personnel.5 Their responsibility is to evaluate vital

signs and examine firefighters, provide a tentative diagnosis, treat them, and dispose

(return to duty, rehabilitation, transport to medical facility). Rehabilitation treatment

should consist of additional monitoring of vital signs, removing personal protective

equipment, providing rest, and giving forced rehydration.5 Additionally, these

evaluations must be recorded on standard forms along with the patient's identity and

complaints and must be signed, timed, and dated.7

Medical personnel on the scene of a fire incident should be competent to identify when

there may be danger of heat stress, to evaluate, and to manage emergencies.7,8

Rehabilitation of stressed firefighters was attempted at the September 6 fire, but

documentation of proper medical evaluation and disposition was not completed. 

 

A prime feature of IMS is the coordination of interagency response.6 There was

purportedly no agreement for the response of emergency medical services to fire ground

emergencies in Sedgwick County. Hence, there was some difficulty in coordinating the

activities of the County Fire Department and those of the EMS.

PASS (Personal Alert Safety System)

The PASS is a small (cigarette pack size) electrical device which 

sounds a distinctive audible alarm when either activated manually or automatically if no

movement of the firefighter can be detected in any 30-second period.9 Most

recommendations are that the PASS devices be worn at all times.4,9

The Sedgwick County Fire Department had provided PASS devices to the firefighters;

however, department policy is that it be worn on the Self Contained Breathing

Apparatus (SCBA) harness. PASS devices were therefore not available for use, as the

firefighters were not wearing the SCBA (reports received by NIOSH indicate that

conditions did not warrant the use of SCBA on this brush fire).10

Personal Identifiers and Assignment

Standard recommendations for fire ground operations require a system to account for the

identity and assignment of fire personnel on the scene.3,4,5 This may consist of roll calls

during the incident, special markings on the individual's coat and/or helmet, etc. 

Additionally, some fire departments distinctly equip firefighters not yet fully qualified

for a particular level of training or experience with a piece of personal protective

equipment (e.g., helmet or protective coat) of a distinctive color so that they and their
Page 5 - Health Hazard Report No. 90-395

operations can receive additional supervision on the fire ground.

Staffing

A two-firefighter engine company is, at a minimum, 50% understaffed and increases the

work effort of the two firefighters by a factor of three.4,11,12 In a brush fire where one

firefighter operates the pump, the second person is left to pull 200' of booster through

rough terrain covered with low-lying undergrowth. At the September 6 fire, the pump

was left unattended and each of the two firefighters advanced a separate booster line up

to 200' in opposite directions from the engine.

Heat Stress

The relevant environmental data were obtained from the National Weather Service,

Wichita Station, for September 6, 1990, and are summarized in Table 1. Firefighters

face a high risk of heat injury under these conditions due to the heavy work they must

perform and the protective clothing they must wear. While insulating firefighters from

the high radiant heat loads at the fire scene, protective clothing also limits the ability to

lose heat through sweat evaporation. However, full firefighter protective clothing was

appropriate for this particular fire incident, due to the potential hazard from exploding

vehicle gas tanks. The protective coat and trousers were constructed as follows: The

outer shell was of Nomex® 7-1/2 oz. Aramid 3®, treated with Zepel® as a water

repellent. A moisture barrier of Gore Tex® with a Nomex® face cloth, and a thermal

liner of 7-1/2 oz. Nomex® face cloth quilted to 100% Nomex® batt face cloth.

The two most serious heat-related illnesses are heat exhaustion and heat stroke. 

According to the NIOSH document, Occupational Exposure to Hot Environments,

Revised Criteria, 198613, symptoms of heat exhaustion include fatigue, nausea,

headache, dizziness, pallor, weakness, and thirst. Factors which may predispose a

person to heat exhaustion include sustained exertion in the heat, failure to replace the

water lost in sweat, and lack of acclimatization. Heat exhaustion responds readily to

such prompt treatments as moving to a cooler environment, resting in a recumbent

position, and administering fluids by mouth.

Heat stroke is the more serious of the heat-related illnesses and is considered a medical

emergency. Symptoms of heat stroke include hot, red, dry skin, a rectal temperature of

104°

F (40°C) or above, confusion, possible convulsions, and/or loss of consciousness. 

Factors which may predispose a person to heat stroke include sustained exertion in the

heat by unacclimatized workers, lack of physical fitness, obesity, recent alcohol intake,

dehydration, individual susceptibility, and chronic cardiovascular disease.11 Immediate

treatment of suspected heat stroke is required. Treatments to reduce body temperature

rapidly include immersing in chilled water, rinsing with alcohol, wrapping in a wet

sheet, and/or fanning with cool, dry air. A physician's care is required to treat possible

secondary disorders such as shock or kidney failure. While heat exhaustion cases

greatly outnumber heat stroke cases, every case of heat exhaustion should be treated as

having the potential to develop into heat stroke.

Acclimatization is a physiological adaptation to heat stress that occurs over a short

period of time. After acclimatization has occurred, the body sweats more while losing

less salt and can maintain a lower core temperature and lower cardiovascular demands. 
Page 6 - Health Hazard Report No. 90-395

A person becomes acclimatized to a certain work intensity and temperature with

repeated exposures to that work load and temperature. Formal acclimatization

procedures may not be necessary for all firefighters; however, training drills should be

held outdoors regularly so that seasonal acclimatization can occur. For additional

protection against heat stress, firefighters may want to perform their regular aerobic

training activities outdoors, especially in the spring and summer.

The metabolic demands of firefighting range from 60 to 100% of maximum aerobic

capacity. Tasks such as stair climbing, roof venting, and rescue operations, when

performed in full gear, have an energy cost of 85 to 100% of maximum capacity and

lead to near maximum heart rates. It is clear from these estimates that a high level of

cardiovascular fitness is an advantage in performing firefighting tasks. The higher level

of fitness would allow a longer work period and provide a greater reserve in case of an

unexpected increase in work demands or in extreme environmental conditions.

There are fire incidents during which even the fittest, most acclimatized firefighter will

be exposed to significant heat stress. For this reason, many fire departments have

adopted formal procedures for on-scene rehabilitation and have incorporated them into

their standard operating procedures manuals. The general goals of rehabilitation are the

following: 1) to provide physical and mental rest, allowing the firefighter to recuperate

from demands of emergency operations and adverse environmental conditions, 2) to

revitalize firefighters by providing fluid replacement and food as needed, and 3) to

provide medical monitoring , including treatment of injuries, to determine if and when

firefighters may return to action.

 V. CONCLUSION

According to the Sedgwick County Coroner, the primary cause of the death of the

firefighter was heat stroke. The factors contributing to this particular death due to heat

stroke include exposure to a hot ambient temperature ($95°F), a high radiant heat load,

and performance of moderate to heavy work while wearing protective clothing. 

Events that preceded the firefighter's death included singly advancing a booster line and

fighting the brush fire for approximately one hour, then resting at the engine alone while

the captain of the two-man engine company reported to command. Upon arriving at the

command station, the captain reported that the firefighter was in need of rehabilitation;

then the captain entered rehabilitation. Over the next few hours several individuals

mistakenly identified other firefighters as the downed firefighter and assured his captain

that he had rested and was then reassigned. The firefighter's body was discovered during

cleanup operations.

 

 On the basis of the information obtained during this investigation, the NIOSH

investigators concluded that a preventable series of events preceded the firefighter's

death.

 VI. RECOMMENDATIONS

1. The positions of command and safety must be separated at complex fire scenes

where there are multiple fire companies and equipment, mutual aid responses,

multiple exposures from a fire ground covering a large area, and so forth. Such
Page 7 - Health Hazard Report No. 90-395

separation will allow the Safety Officer to function in a manner consistent with the

duties recognized as appropriate and as established by department standard

operating procedures.

2. The Department should make the wearing of PASS devices mandatory for all

firefighters any time they are involved in rescue, firefighting, or other hazardous

duties. Rescue operations should begin immediately upon such an alarm or

whenever there is difficulty in locating operating crews.

3. Firefighters operating at emergency incidents must always operate in teams of two

or more (buddy system). A buddy system allows two firefighters to observe each

other for signs of medical emergencies such as heat stress and to provide help to

each other if needed. Another obvious advantage of a buddy system is to permit

firefighters to share work, thereby reducing the metabolic heat they produce and in

turn reducing the heat stress. All firefighter team members operating in hazardous

areas must be in communication with each other and with incident command

through visual, audible, physical, electronic, or other means in order to provide

assistance in case of emergency.

4. To aid in the overall management of the fire scene and to assist the fire ground

commander and firefighter teams in recognition and control, personal markings to

insure positive identification of individuals, such as fluorescent and retroreflective

name tags/letters should be affixed to protective coats, helmets, or equipment.

5. Inexperienced firefighters must be provided with additional supervision. 

Experience must not be solely dependent on the period of employment, but also on

the type of fires fought (brush, residential, commercial, etc.) If there are only one

or two of a particular type of fire a year, it may take more than 1 year (usual

probationary period) to gain the necessary experience in fighting that type of fire.

6. Search and rescue operations should be initiated immediately upon reports of

personnel in trouble or upon failure to locate operating crews.

7. The replacement of fluids (water) lost in sweat is the most practical work practice a

firefighter can adopt to protect himself against heat-related illness. Since thirst is

an insufficient indicator that lost fluids have been replaced, firefighters should be

encouraged to drink beyond the point of thirst while on a call or after an aerobic

workout. Ideally, 5 to 7 ounces of water should be consumed every 15 to 20

minutes during firefighting activities. Salt tablets should not be used.

8. Regardless of the size of the fire department, procedures concerning rehabilitation

should be included in the department's standard operation procedures. These

procedures should include guidelines for initiating and enforcing rehabilitation

efforts and managing the resources and personnel within the rehabilitation sector. 

The responsibility for initiating the appropriate rehabilitation efforts should belong

to the incident commander. When the incident size is large or the level of physical

exertion and/or environmental conditions are extreme, the implementation of

rehabilitation procedures should be considered by the incident commander. The

rehabilitation sector should be located in an area outside the operational activity
Page 8 - Health Hazard Report No. 90-395

area, where protective equipment and clothing can be safely removed. Resources

should consist of a mobile canteen, a shady or air conditioned area for resting, and

an advanced life support unit.

9. The Department should conduct periodic reviews of heat stress-related topics for

fire department members. Such topics as recognizing the signs and symptoms of

heat-related illnesses, rehydration after firefighting and exercise activities, and

acclimatization should be included in the training. The Sedgwick County Fire

Department's Health/Fitness Manual could be used as a resource for this training. 

 VII. REFERENCES

1. National Fire Protection Association. Recommendations for Developing Fire

Protection Services for the Public. National Fire Protection Association: Boston,

MA: 1989 [NFPA 1201-1989].

2. National Fire Administration. The Incident Command System. National Fire

Administration: Emmitsburg, MD: [NFA-ICS-SM].

 3. National Fire Protection Association. Standard on Fire Department Incident

Management System. National Fire Protection Association: Quincy, MA: 1990

[NFPA 1561-1990].

4. National Fire Protection Association. Standard on Fire Department Occupational

Safety and Health. National Fire Protection Association: Quincy, MA: 1987

[NFPA 1500-1987].

5. Brunacini, A.V. Fire Command. National Fire Protection Association: Boston:

1987.

6. Oklahoma State University. Incident Command System. The Oklahoma State

University: Stillwater: 1983.

7. Grant, H. and Murray, R. Emergency Care. Brady: Bowie, MD: 1989.

8. National Fire Protection Association. Standard on Fire Fighter Medical

Technicians Professional Qualifications. National Fire Protection Association:

Boston, MA: 1985 [NFPA 1004-1985].

9. National Fire Protection Association. Standard on Personal Alert Safety Systems. 

National Fire Protection Association: Boston, MA: 1988 [NFPA 1982-1988].

 10. Brotherhood, J.R. et al. Fire Fighters Exposure to Carbon Monoxide During Australian

Brushfires. Am Ind Hyg Assoc J, 51(4)234.

 11. National Fire Protection Association. Principles of Fire Protection. National Fire

Protection Association: Boston, MA: 1988.
Page 9 - Health Hazard Report No. 90-395

 12. Coleman, R.J., Granito, J.A. Managing Fire Services. International City Management

Association. 2nd edition: Washington, D.C.: 1988. 

 13. NIOSH [1986]. Criteria for a recommended standard: occupational exposure to hot

environments. Cincinnati, OH: U.S. Department of Health and Human Services. 

Public Health Service, Centers for Disease Control, National Institute for Occupational

Safety and Health, DHHS (NIOSH) Publication No. 86-113.

 VIII. AUTHORSHIP AND ACKNOWLEDGEMENTS

Report Prepared by: Ruth A. Shults, R.N., M.P.H.

Health Officer

Medical Section

Hazard Evaluations and Technical

 Assistance Branch

Gary P. Noonan, M.P.A.

Section Chief

Protective Equipment Section

Protective Technology Branch

Division of Safety and Research

Nina Turner, Ph.D.

Respiratory Physiologist

Protective Equipment Section

Protective Technology Branch

Division of Safety and Research

 Background Information: Richard M. Ronk

Safety Engineer

Division of Safety and Research
Page 10 - Health Hazard Report No. 90-395

 IX. DISTRIBUTION AND AVAILABILITY OF REPORT

Copies of this report may be freely reproduced and are not copyrighted. Single copies of

this report will be available for a period of 90 days from the date of this report from the

NIOSH Publications Office, 4676 Columbia Parkway, Cincinnati, OH 45226. To

expedite your request, include a self-addressed mailing label along with your written

request. After this time, copies may be purchased from the National Technical

Information Service, 5285 Port Royal, Springfield, VA 22161. Information regarding

the NTIS stock number may be obtained from the NIOSH Publications Office at the

Cincinnati address.

Copies of this report have been sent to:

1. Sedgwick County Fire Department, Wichita, Kansas

2. International Association of Firefighters, Local 2612

3. International Association of Firefighters,

 Washington, D.C.

4. Occupational Safety and Health Administration

Copies of this report shall be posted by the employer in a prominent place accessible to

the employees for a period of 30 calendar days.
TABLE 1

Environmental Conditions

September 6, 1990, Wichita, Kansas

International Association of Firefighters (IAFF)

Sedgwick County, Kansas

 

HETA 90-395

 

_____________________________________________________________________

Time Temp Dew Point Wind Speed Visibility

 (°F) (°F) 

_____________________________________________________________________

11:52 AM 95 55 24 Scattered to broken

12:51 PM 95 57 23 cloud cover, 12 miles

 1:51 PM 95 57 22 visibility

 2:51 PM 98 52 18 

 3:50 PM 96 53 26 

_____________________________________________________________________
Page 12 - Health Hazard Report No. 90-395

 TABLE 2

 Recommended Exposure Limits Based on Dry Bulb

 Temperature for Firefighters in Turnout Gear (°F)*

 International Association of Firefighters (IAFF)

 Sedgwick County, Kansas

 

 HETA 90-395

_________________________________________________________________

Work/Rest Regimen Work Load

 Moderate Heavy

_________________________________________________________________

Continuous work 80°F 77°F

75% Work/ 

25% Rest, each hour 82°F 78°F

50% Work/

50% Rest, each hour 85°F 82°F

25% Work/

75% Rest, each hour 88°F 86°F

_________________________________________________________________

* Temperatures represent dry bulb values substituted for Wet Bulb

 Globe Temperature (WBGT) values in Table 1, p.88, of the Threshold Limit Values.2
APPENDIX I

Chronology of The Fire

The fire under investigation occurred in a rural residential area in the far southeast corner of

Sedgwick County, Kansas. Lots in the immediate vicinity range in size from 7/10 to 1/2 acres. 

Most of the residences are prefabricated construction. The gently rolling terrain is covered by a

heavy weed undergrowth and small trees. The soil is sandy.

Lot 11, on which the fire began, is nearly rectangular and covers about 1/2 acres (Figure 1). One

prefabricated house sets approximately 110 feet west of the road near the south border of the lot

and faces east south-east. Lot 10 is north of Lot 11 and is of similar size and shape, but has

fewer trees. A salvage yard, with over 50 junked automobiles, covers most of Lot 10. An

uninhabited mobile home is near the north edge of the property line. 

EMS Activities

SCFD did not have a formal agreement as to the role of Sedgwick County EMS in the

rehabilitation of fire fighters at fire scenes. However, it is common practice for EMS to be called

to stand by in the event that a fire fighter requires emergency treatment and transport. However,

according to transcripts and charting of the incident, an EMS medic was assigned to be in charge

of medical operations at the scene. SCFD Medical Quality Control Officer, an emergency

medical intensive care technician (EMICT), was assigned to be an aid for the incident

commander. However, she assisted with rehabilitation of several firefighters. 

A Sedgwick County EMS ambulance arrived at around 12:35 p.m. and parked next to the

command post. The two EMICTs provided fluids to firefighters as they approached the

command post. When the EMICTs thought firefighters appeared exhausted or overly hot, they

requested the firefighters to "rehab" inside the air-conditioned ambulance. Blood pressure and

pulse were checked on at least some of the firefighters who entered rehabilitation, but firefighters

were not asked to identify themselves and no recordings of names or vital signs were made. 

On several occasions EMICTs carried fluids to firefighters who were resting nearer the fire. In

one such instance, an EMICT assisted a firefighter who was resting under a small tree located

southeast of the house on Lot 11. No personal or station identification is displayed on SCFD

personal protective clothing, and the EMICT did not ask the firefighter his name, but was later

told by SCFD personnel that the firefighter was Firefighter A. Upon reviewing available

accounts of this incident, we are reasonably certain that the individual who EMS assisted was not

Firefighter A.

Deceased Firefighter's Activities 

Firefighter A reported to work at 7:00 a.m. on September 6, 1990. As part of their usual physical

fitness routine, the station crew drove to a nearby city park to exercise where Firefighter A

jogged his usual three miles. Upon 
returning to the station, he had begun to prepare his lunch when the fire alarm sounded. Leaving

his lunch behind, he rode in Engine six (E-6) with the shift captain to the fire scene. They were

the first firefighters to arrive; it was 11:55 a.m. Within 15 minutes of arriving at the scene, the

captain had requested additional engines and tanks, volunteers from nearby small towns, and for

an EMS ambulance to stand by at the scene. 

The two man crew maneuvered E-6 behind the house and down a gradual incline to a clearing

near the head of the fire. There, they began fighting the fire (Figure 1). As additional units

arrived, the captain assigned them to other areas in an attempt to contain the rapidly spreading

fire. 

At about 12:20 p.m., the captain of E-6 radioed that he and Firefighter A had been fighting the

fire with separate booster lines, and that they were "just worn out." Similar requests for relief

were radioed at 12:27 and 12:41 p.m.

Another SCFD firefighter stated that he reported to E-6 upon arriving at the fire scene in a tanker

truck and saw Firefighter A and the captain. According to the tape transcript, this occurred

sometime between 12:27 p.m. and 12:41 p.m. Then, he and a volunteer firefighter pulled lines

from the tanker across the fence separating Lot 11 and Lot 10 and began extinguishing the fire

that had spread north into the salvage yard. The two continued fighting the fire until the tanker

ran out of water. After refilling the tanker, the SCFD firefighter returned to E-6 to find that it

had been abandoned. 

As reported in conversations with the captain, both he and Firefighter A fought the fire until they

were exhausted. Both returned to E-6, lowered their trousers, and rested. At that time, the

assistant chief arrived at the address, but he was unable to find E-6's location. After several

attempts to explain his location to the chief over the radio, the captain stated that he would "try to

make it to the road" to accompany the chief into the fire scene. The captain instructed Firefighter

A to remove his personal protective clothing, to get a drink of water, and to rest on the tailgate of

E-6 while the captain reported to the chief. The captain stated that he would return with some

relief firefighters, and then left, walking northeast along the fence line separating Lot 11 and Lot

10. 

The chief had established the command post in a vehicle parked on the road adjacent to Lot 10

(Figure 1). An ambulance was parked next to the command post, with technicians standing by,

to treat injured or exhausted firefighters. As the captain approached the command post, he was

overcome by exhaustion and ordered by the chief to enter the ambulance for rehabilitation. The

captain advised the chief that Firefighter A was tired and needed to be relieved. At about 1:35

p.m. the order to have Firefighter A report to the command post was radioed and receipt of the

order was anonymously acknowledged. 

While the captain was in the EMS unit, a request to assist a downed firefighter was issued. 

Believing the firefighter to be Firefighter A, the captain attempted to leave rehabilitation to check

on his crew member. He was instructed by the Medical Quality Control Officer to remain in the

unit. The downed firefighter was not Firefighter A. Upon leaving rehabilitation, the captain

inquired as to Firefighter A's status and was told that he had been assigned to drive a tank truck.

Firefighter A's body, dressed in full personal protective clothing, was discovered at

approximately 4:00 p.m. by a volunteer firefighter. It was located west and slightly north of the

house on Lot 11 in a brush covered, unburned area near the barbed wire fence separating Lots 10

and 11 (Figure 1). The terrain in this area is wooded and has a gradual downward slope away

from the house. This may have prevented others from seeing the downed firefighter from a

distance. The body was lying supine, on a car wheel, near the barbed wire fence separating Lots

10 and 11. Assessment by EMS personnel revealed rigor mortis. The Sedgwick County
Page 15 - Health Hazard Report No. 90-395

Coroner's Report of death listed the cause of death to be heat stroke. Drug and alcohol screening

results were negative.
APPENDIX II

Additional Heat Stress Information

The following sections provide additional information and references on heat stress and its

prevention. The information is applicable to firefighting as well as other occupational exposures

to hot environments.

Heat Stress Indices and Work/Rest Cycles

During the past fifty years, a variety of schemes has been developed for predicting the heat stress

workers might experience in hot work environments. These schemes rely on various heat stress

indices which include some or all of the important environmental factors (dry bulb, wet bulb, and

mean radiant temperatures and air velocity). Since the early 1970's, the Wet Bulb Globe

Temperature (WBGT) index has become the most frequently used and recommended heat stress

index.1,2 The WBGT index is based on objective and subjective data obtained from individuals

exposed to various combinations of environmental and metabolic heat stress factors. The

calculation of the WBGT for indoors is:

 WBGT = 0.7Tnwb + 0.3Tg

for outdoors:

 WBGT = 0.7Tnwb + 0.2Tg + 0.1Tdb

Tnwb = natural wet bulb temperature

Tg = black globe temperature

Tdb = dry bulb temperature

NIOSH has published Recommended Exposure Limits (RELs) based on WBGT for metabolic

workloads ranging from 116 Watts (very light work) to 580 Watts (very heavy work).3 These

RELs are based on the assumption that nearly all acclimatized workers with adequate water

intake should be able to function effectively without exceeding a deep body temperature of

100.4°F (38°C). These limits apply to the "standard worker" of 154 lbs (70 kg) body weight and

19.4 ft2 (1.8 m2) body surface area wearing lightweight work clothing. When other than

lightweight, single layer clothing ensembles are worn, the WBGT limits must be lowered

accordingly (6 to 10°C for impermeable ensembles) (4). When a vapor and air impermeable

encapsulating ensemble is worn, the dry bulb or adjusted dry bulb temperature can be substituted

for the WBGT.3

 When the above recommendation is applied to firefighters wearing full turnout

gear, the resulting Recommended Exposure Limits for four basic work/rest cycles are shown

below. It has been estimated that a firefighter's metabolic rate at a fire scene is a time-weighted

average of between 300 and 400 watts.4 This work intensity corresponds to the moderate work

load presented in Table 2.2

Medical Monitoring

NIOSH has recommended that physiologic monitoring consisting of an oral temperature and/or

pulse rate when impermeable clothing is worn at an adjusted dry bulb temperature exceeding

68°F. The suggested frequency of physiologic monitoring for moderate work varies from once

every two hours at an adjusted dry bulb temperature of 90°F (32°C).3 A recovery heart rate,

taken during the third minute of seated rest, exceeding 90 beats per minute, and a recovery heart

rate taken during the first minute of rest minus the third minute recovery heart rate of 10 beats

per minute or fewer indicate excessive heat strain. An oral temperature of 100.4°F (38°C) or
Page 17 - Health Hazard Report No. 90-395

above is also indicative of heat stress. Firefighters should not be allowed to return to work until

their heart rate and oral temperature are below these limits.

Personal Cooling Devices

When large fires must be suppressed during periods of hot weather, the air temperature

surrounding a firefighter ranges from 140 to 572°F.5 One possible solution for avoiding heat

stress under these extreme conditions is the use of auxiliary cooling devices. 

Several personal cooling devices which have been evaluated in various industries include watercooled garments, air-cooled garments, ice packet vests and wettable cover garments. A nonflame resistant, wetted cover garment would not meet the safety requirements for firefighters'

protective clothing, and an air-cooled garment would severely limit mobility. Of the two

remaining possibilities, ice packet vests would provide the more practical and economical

solution to heat stress problems. Further investigation into the feasibility of using personal

cooling devices during fire fighting is needed.4
APPENDIX II REFERENCES

1. International Standards Organization (ISO). Hot environments - Estimation of the Heat

Stress on Working Man, Based on the WBGT-Index (Wet Bulb Globe Temperature).ISO

7243, 1989.

2. ACGIH [1990]. Threshold limit values and biological exposure indices for 1990-1991. 

Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

3. NIOSH [1986]. Criteria for a recommended standard: occupational exposure to hot

environments. Cincinnati, OH: U.S. Department of Health and Human Services. Public

Health Service, Centers for Disease Control, National Institute for Occupational Safety and

Health, DHHS (NIOSH) Publication No. 86-113.

4. Goldman, R.F. Heat stress in firefighting: the relationship between work, clothing, and

environment. Fire Engineering. (May):47-52;1990.

5. Utech, H.P. High Temperature vs. Fire Equipment. International Fire Chief. 39:26-27; 1973.