Heat Exhaustion

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Heat exhaustion definition and facts

  • Heat exhaustion is one part of the spectrum of heat-related illnesses that begin with heat cramps, progresses to heat exhaustion, and finally to heat stroke.
  • The body cools itself by sweating and allowing that sweat to evaporate. This requires enough fluid in the body to make sweat, air circulating across the skin, and low enough air humidity to allow that sweat to evaporate.
  • Activity in a hot environment can overwhelm the body's ability to cool itself, causing heat-related symptoms.
  • Symptoms of heat exhaustion include profuse sweating, weakness, nausea, vomiting, headache, lightheadedness, and muscle cramps.
  • Heat exhaustion can progress to heat stroke when the body's temperature regulation fails. The affected individual develops a change in mental status, becomes confused, lethargic and may have a seizure, the skin stops sweating, and the body temperature may exceed 106 F (41 C ). This is a life-threatening condition and emergency medical attention is needed immediately.
  • Treatment for heat exhaustion includes recognizing the symptoms, stopping the activity, and moving to a cooler environment. Rehydration with water or a sports drink is the cornerstone of treatment for heat exhaustion. If nausea or vomiting prevents the affected individual from drinking enough water, intravenous fluids may be required.
Medically Reviewed by a Doctor on 7/16/2014

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Dehydration due to heat exhaustion

6 Ways to Prevent Heat Exhaustion

Heat exhaustion is a heat-related illness that occurs when you are exposed to high temperatures and you sweat excessively. This causes dehydration due to loss of water and salt.

Signs and symptoms of heat exhaustion include profuse sweating, dizziness, weakness, headache, nausea, vomiting, muscle cramps, or dark-colored urine (a sign of dehydration).