Heat exhaustion: First aid

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By Mayo Clinic staff

Heat exhaustion is one of the heat-related syndromes, which range in severity from mild heat cramps to heat exhaustion to potentially life-threatening heatstroke.

Signs and symptoms of heat exhaustion often begin suddenly, sometimes after excessive exercise, heavy perspiration and inadequate fluid intake. Signs and symptoms resemble those of shock and may include:

  • Feeling faint or dizzy
  • Nausea
  • Heavy sweating
  • Rapid, weak heartbeat
  • Low blood pressure
  • Cool, moist, pale skin
  • Low-grade fever
  • Heat cramps
  • Headache
  • Fatigue
  • Dark-colored urine

If you suspect heat exhaustion:

  • Get the person out of the sun and into a shady or air-conditioned location.
  • Lay the person down and elevate the legs and feet slightly.
  • Loosen or remove the person's clothing.
  • Have the person drink cool water.
  • Cool the person by spraying or sponging him or her with cool water and fanning.
  • Monitor the person carefully. Heat exhaustion can quickly become heatstroke.

If fever greater than 102 F (38.9 C), fainting, confusion or seizures occur, dial 911 or call for emergency medical assistance.

FA00020

Jan. 4, 2008

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