Heat Safety

Heat Stress

Every year, dozens of workers die and thousands more become ill while working in extreme heat or humid conditions.

Heat stress is a series of conditions where the body is under stress from overheating. Heat-related illnesses include heat cramps, heat exhaustion, heat rash, or heat stroke, each with its own symptoms.

Those at greatest risk of heat stroke include the elderly, children, and people with medical conditions. However, even young and healthy individuals can succumb to heat if they participate in strenuous physical activities during hot weather. Heat stress can be induced by high temperatures, heavy work loads, and clothing inappropriate for the heat and humidity.

Signs of heat stroke are often overlooked by those affected. The individual may at first be confused or unable to concentrate, followed by more severe symptoms, such as fainting and/or collapsing. If heat stress symptoms occur, move the victim to a cool, shaded area, give him or her water, and immediately contact a supervisor or another individual to provide assistance.

At-risk Employees

Some employees are more like to be affected by heat disorders than others. Employees with heart, lung, or kidney disease, and those on medications are more likely to experience heat stress problems. Diet pills, sedatives, tranquilizers, caffeinated drinks, and excessive alcohol consumption can worsen heat stress effects.

It often takes two to three weeks for employees to become acclimated to a hot environment. Employees should be cautious about heat stress during the first few weeks of working outside in the summer months, when coming back from vacation, starting a new job and during summer’s first heat wave. Precautions should be taken anytime temperatures are elevated (approaching 90 degrees F) and the job is physically demanding.


  • Heat Exhaustion
    • Move person to a cooler environment
    • Lay person down and loosen clothing
    • Apply cool, wet cloths to as much of the body as possible
    • Fan or move victim to air conditioned room
    • Offer sips of water
    • If person vomits more than once, seek immediate medical attention
  • Heat Stroke
    • Heat stroke is a severe medical emergency. Call 911 or get the victim to a hospital immediately. Delay can be fatal.
    • Move the victim to a cooler, preferably air-conditioned, environment
    • Reduce body temperature with cool cloths or bath
    • Use fan if heat index temperatures are below the high 90s. A fan can make you hotter at higher temperatures
    • Do NOT give fluids.

Prevention of Heat Stress: Workers

  • Know and learn to recognize the symptoms of heat stress. Pace yourself and take adequate rest periods in shade or a cooler environment.
  • Use adequate fans for ventilation and cooling, especially while wearing personal protective equipment (PPE).
  • Wear light-colored, loose clothing (unless working around equipment with moving parts).
  • Keep yourself shaded from direct heat when possible.
  • Drink plenty of water, when exposed to hot environments the body needs more water.

Prevention of Heat Stress: Supervisors

  • Allow time for employees to adjust to hot jobs when possible.
  • Adjust the work schedule if possible. Assign heavier work during the cooler part of the day.
  • Reduce the workload. Increase the use of equipment on hot days to reduce physical labor.
  • Establish a schedule for work and rest periods during hot days.
  • Train workers to recognize signs and symptoms of heat disorders and be prepared to five first aid if necessary.
  • Remember, individual employees vary in their tolerance to heat stress conditions.