Extreme heat kills by pushing the body beyond its limits.  In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature. Extreme heat can result in heat stroke, heat exhaustion, heat cramps, or heat rashes. Extreme heat can also increase the risk of injuries in workers as it may result in sweaty palms, fogged-up safety glasses, and dizziness.

Prevention of extreme heat situations is very important to know and understand.  Listed below are two different types of extreme heat while on the job. Included is information on the symptoms and first aid that can be used to assist someone suffering from extreme heat.

Heat Stroke

Heat stroke is the most serious heat-related disorder. It occurs when the body becomes unable to control its temperature:  The body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. When heat stroke occurs, the body temperature can rise to 106 degrees or higher within 10 to 15 minutes. Heat stroke can cause death or permanent disability if emergency treatment is not given.


Symptoms of heat stroke include the following:

  • Hot, dry skin (no sweating)
  • Hallucinations
  • Chills
  • Throbbing headache
  • High body temperature
  • Confusion and/or dizziness
  • Slurred speech

First Aid

  • Call a supervisor for help; if the supervisor is not available, call 911
  • Move the sick worker to a cool shaded area
  • Cool the worker such as; soaking the worker’s clothes with water

Heat Exhaustion

Heat exhaustion is the body’s response to an excessive loss of water and salt, usually through excessive sweating. Workers most prone to heat exhaustion are those that are elderly, have high blood pressure, and those working in a hot environment.


Symptoms of heat exhaustion include the following:

  • Heavy sweating
  • Extreme weakness or fatigue
  • Dizziness, confusion
  • Nausea
  • Clammy, moist skin
  • Pale or flushed complexion
  • Muscle cramps
  • Slightly elevated body temperature
  • Fast and shallow breathing

First Aid

Treat a worker suffering from heat exhaustion by doing the following:

  • Have the worker rest in a cool, shaded or air-conditioned area
  • Have the worker drink plenty of water, clear juice or a sports beverage

Recommendations for Employees who are exposed to Extreme Heat

  • Wear light-colored, loose-fitting, breathable clothing such as cotton. (Avoid non-breathing synthetic clothing);
  • Gradually build up to heavy work;
  • Schedule heavy work during the coolest parts of the day;
  • Take more breaks in extreme heat and humidity. (Take breaks in the shade or cool area when possible);
  • Drink water frequently. Drink enough water that you never become thirsty. (Avoid drinks with caffeine, or large amounts of sugar);
  • Be aware that protective clothing or personal protective equipment may increase the risk of heat stress;
  • Fan and mist the worker with water, and apply ice (ice bags or ice towels)
  • Monitor your physical condition and that of your co-workers, listen to your body.