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Heat Exhaustion

Heat Exhaustion Facts

  • Heat exhaustion is a condition that occurs when the body overheats.
  • Heat exhaustion is caused by the failure of the body's cooling mechanism to maintain a normal core temperature.
  • Symptoms of heat exhaustion may include
  • Heat exhaustion is diagnosed based on the patient's history of heat exposure, physical exam, symptoms and a body core temperature that is elevated.
  • Treatment for heat exhaustion includes removing the individual from the hot environment, cooling the body, and rehydration.
  • Complications of heat exhaustion include progression to heat stroke, a medical emergency that can lead to permanent organ damage and death. In pregnant women, it may harm the fetus.
  • Heat exhaustion can be prevented by adequate fluid intake and decreasing strenuous activity in hot environments. Pregnant women develop more heat intolerance as their pregnancy advances.
  • Animals (dogs and cats, for example) can develop heat exhaustion, and the treatment and prevention is similar to that of humans.

What Causes Heat Exhaustion?

Patient Comments

The main cause of heat exhaustion is failure of the body's cooling mechanism (mainly evaporative sweating) to maintain a normal core body temperature, resulting in the body overheating. This can occur in adults, children and animals (dogs and cats, for example). Factors that can contribute to heat exhaustion include

  • strenuous work or exercise in a warm or hot environment,
  • dehydration,
  • alcohol intake, and
  • wearing clothing that inhibits evaporative cooling of the body.

The elderly and children under 5 years of age are at higher risk for developing heat exhaustion.

Medically Reviewed by a Doctor on 11/10/2016
Medical Editor:

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Dehydration Pictures: Tips to Stay Hydrated

Causes of Dehydration: Sweat

The body can lose significant amounts of water when it tries to cool itself by sweating. Whether the body is hot because of the environment (for example, working in a warm environment), intense exercising in a hot environment, or because a fever is present due to an infection; the body uses a significant amount of water in the form of sweat to cool itself. Depending upon weather conditions, a brisk walk will generate up to 16 ounces of sweat (one pound of water).

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