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Dangers of working in the heat

Dangers of working in the heat

Every year, dozens of workers die and thousands more become ill while working in extreme heat or humid conditions. There are a range of heat illnesses and they can affect anyone, regardless of age or physical condition. Under Occupational Safety and Health Administration (OSHA) law, employers are responsible for providing workplaces free of known safety hazards. This includes protecting workers from extreme heat. An employer with workers exposed to high temperatures should establish a complete heat illness prevention program.

Working in outdoor and indoor heat environments

Although illness from exposure to heat is preventable, every year, thousands become sick from occupational heat exposure, and some cases are fatal. Most outdoor fatalities, 50% to 70%, occur in the first few days of working in warm or hot environments because the body needs to build a tolerance to the heat gradually over time. The process of building tolerance is called heat acclimatization. Lack of acclimatization represents a major risk factor for fatal outcomes.

Occupational risk factors for heat illness include; heavy physical activity, warm or hot environmental conditions, lack of acclimatization, and wearing clothing that holds in body heat. Hazardous heat exposure can occur indoors or outdoors, and can occur during any season if the conditions are right, not only during heat waves. The following are some industries where workers have suffered heat-related illnesses:

  • Outdoor: agriculture, construction, landscaping, oil and gas well operations, etc.
  • Indoor: bakeries, kitchens, laundries, steel mills, foundries, etc.

Heat-related illnesses 

Several heat-related illnesses can affect workers. Some of the symptoms are non-specific; when a worker is performing physical labor in a warm environment, any unusual symptom can be a sign of overheating. Heat-related illness includes; heat stroke, heat exhaustion, heat cramps, heat syncope, and heat rash. Symptoms and signs include; confusion, slurred speech, unconsciousness, seizures, heavy sweating, rapid heart rate, fatigue, irritability, thirst, nausea or vomiting, dizziness, fainting, red bumps on skin, etc.

First aid

OSHA’s General Industry Medical Services and First Aid standards 29 CFR 1910.151 and Construction Industry 29 CFR 1926.50 require the ready availability of first aid personnel and equipment. First aid for heat-related illness involves the following principles:

  • Take the affected worker to a cooler area (e.g., shade or air conditioning)
  • Remove outer layers of clothing, especially heavy protective clothing
  • Cool the worker immediately. Use active cooling techniques such as immersing the worker in cold water or an ice bath.
  • Place ice or cold wet towels on the head, neck, trunk, armpits, and groin
  • Use fans to circulate air around the worker
  • Never leave a worker with heat-related illness alone. The illness can rapidly become worse. Stay with the worker.
  • When in doubt, call 911!


Heat-related illnesses can be prevented. Prevention requires employers and workers to recognize heat hazards. Management should commit to:

  • Taking extra precautions to protect new workers
  • Training supervisors and workers to control and recognize heat hazards
  • Determining total heat stress is too high for each worker by considering both daily conditions and the possibility of carryover effect
  • Implementing engineering and administrative controls to reduce heat stress
  • Providing sufficient rest, shade, and fluids

Source: Occupational Safety and Health Administration (OSHA)