- Safety and Health Topics
- Occupational Heat Exposure
Occupational Heat Exposure
Most heat-related health problems can be prevented, or the risk of developing them can be reduced. For indoor environments, refer to the information below.
The best way to prevent heat-related illness is to make the work environment cooler. A variety of engineering controls can reduce workers' exposure to heat:
- Air conditioning (such as air-conditioned crane or construction equipment cabs, air conditioning in break rooms).
- Increased general ventilation.
- Cooling fans.
- Local exhaust ventilation at points of high heat production or moisture (such as exhaust hoods in laundry rooms).
- Reflective shields to redirect radiant heat.
- Insulation of hot surfaces (such as furnace walls).
- Elimination of steam leaks.
- Employers should have an emergency plan in place that specifies what to do if a worker has signs of heat-related illness, and ensures that medical services are available if needed.
- Employers should take steps that help workers become acclimatized (gradually build up exposure to heat), especially workers who are new to working in the heat or have been away from work for a week or more. Gradually increase workloads and allow more frequent breaks during the first week of work.
- Workers must have adequate potable (safe for drinking) water close to the work area, and should drink small amounts frequently.
- Rather than being exposed to heat for extended periods of time, workers should, wherever possible, be permitted to distribute the workload evenly over the day and incorporate work/rest cycles. (See About Work/Rest Schedules.)
- If possible, physical demands should be reduced during hot weather, or heavier work scheduled for cooler times of the day.
- Rotating job functions among workers can help minimize overexertion and heat exposure.
- Workers should watch out for each other for symptoms of heat-related illness and administer appropriate first aid to anyone who is developing a heat-related illness.
- In some situations, employers may need to conduct physiological monitoring of workers - see Monitoring Workers at Risk of Heat-related Illness.
Personal Protective Equipment
Workers should be aware that use of certain personal protective equipment (e.g., certain types of respirators and impermeable clothing) can increase the risk of heat-related illness.
In some situations, special cooling devices can protect workers in hot environments:
- In some workplaces, insulated gloves, insulated suits, reflective clothing, or infrared reflecting face shields may be needed.
- Thermally conditioned clothing might be used for extremely hot conditions; for example:
- A garment with a self-contained air conditioner in a backpack.
- A garment with a compressed air source that feeds cool air through a vortex tube.
- A plastic jacket whose pockets can be filled with dry ice or containers of ice.
Workers and supervisors should be trained about the hazards of heat exposure and their prevention. Topics should include:
- Risk factors for heat-related illness.
- Different types of heat-related illness, including how to recognize common signs and symptoms.
- Heat-related illness prevention procedures.
- Importance of drinking small quantities of water often.
- Importance of acclimatization, how it is developed, and how your worksite procedures address it.
- Importance of immediately reporting signs or symptoms of heat-related illness to the supervisor.
- Procedures for responding to possible heat-related illness.
- Procedures to follow when contacting emergency medical services.
- Procedures to ensure that clear and precise directions to the work site will be provided to emergency medical services.
Extreme Heat Alerts
OSHA has partnered with the National Oceanic and Atmospheric Administration (NOAA) on weather service alerts. NOAA's alerts are based on a "heat index" that indicates how hot it really feels when relative humidity is factored with the actual air temperature. This information can help workers and employers take precautions in a timely way to prevent heat-related illness.
- OSHA Technical Manual (OTM) Chapter – Heat Stress. OSHA Directive TED 01-00-015 [TED 1-0.15A], (September 15, 2017). Includes useful sections on heat illness, prevention programs, assessment and screening for heat stress in the workplace.
- Working Outdoors in Warm Climates. OSHA Fact Sheet, (September 2005).
- Protecting Yourself in the Sun. OSHA Publication 3166, (2003). Also available in Spanish. Contains suggestions to protect employees from harmful ultraviolet (UV) radiation.
- Protecting Yourself From Heat Stress. U.S. Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 2010-114, (April 2010). Fast Facts pocket card.
- Occupational Safety and Health Guidance Manual for Hazardous Waste Site Activities. NIOSH/OSHA/USCG/EPA Chapter 8, (1985). Provides guidance for performing physiological monitoring of workers at hot worksites.
- Ramsey, J. D., F. N. Dukes-Dobos, and T. E. Bernard. "Evaluation and control of hot working environments: Part I -- Guidelines for the practitioner." International Journal of Industrial Ergonomics 14(1994): 119-127. Provides a review of guidelines for practitioners in the evaluation and control of hot working environments.
- Ramsey, J. D., F. N. Dukes-Dobos, and T. E. Bernard. "Evaluation and control of hot working environments: Part II -- Knowledge base for guide." International Journal of Industrial Ergonomics 14(1994): 129-138. Includes a review of the scientific basis of the guidelines for the evaluation and control of hot working environments.
- Heat Injury Prevention & Sun Safety. U.S. Army Public Health Command.
- Beat the Heat. Centers for Disease Control. Podcast discussing symptoms of heat-related illnesses and how to prevent them.