Hyperthermia (cont.)

Medical Author:
Medical Editor:

Heat exhaustion

Heat exhaustion is the body's response to an excessive loss of water and salt contained in sweat as a result of engaging in physical activity (work or exercising) in a hot environment. The body temperature may be normal or mildly elevated, but not above 104 F (40 C). It often occurs in individuals who are not accustomed to working or exercising in the heat. The symptoms may range from minor complaints to more pronounced symptoms, however the affected individual will not experience the central nervous system manifestations noted with heat stroke. Many cases of heat exhaustion can be treated outside of the hospital setting however it is important to understand that heat exhaustion can progress to heat stroke if not properly addressed in a timely fashion.

What are the signs and symptoms of heat exhaustion?

Warning signs of heat exhaustion include:

  • a normal or mildly elevated body temperature,
  • heavy sweating,
  • pallor (paleness),
  • muscle cramps and muscle pain,
  • fatigue,
  • weakness,
  • dizziness and lightheadedness,
  • headache, and
  • nausea.

The skin may be cool and moist. The affected individual's pulse rate may be fast, and breathing may be fast and shallow. If heat exhaustion is untreated and heat exposure continues, it may sometimes progress to heat stroke.

What is the treatment for heat exhaustion?

Cooling measures that may be effective include:

  • drink cool, non-alcoholic beverages, such as water and sports drinks,
  • eat salty snacks,
  • rest in the shade or in an air-conditioned environment,
  • take a cool shower or bath, and
  • loosen or remove restrictive clothing.

Seek medical attention immediately if:

  • the symptoms are severe or worsening, or
  • the affected individual has serious underlying health problems (for example, heart disease or diabetes).

Otherwise, help the person cool off, and seek medical attention if symptoms worsen or last longer than one hour.

Medically Reviewed by a Doctor on 6/30/2015

Dehydration Pictures Slideshow: Causes, Symptoms and Tips to Stay Hydrated

Patient Comments

Viewers share their comments

Heat-Related Illness - Causes Question: What are the triggers or causes of your heat-related illness? How do you avoid these triggers?
Heat-Related Illness - Heat Cramps Symptoms Question: What were your symptoms of heat rash, and what was the treatment?
Heat-Related Illness - Experience Question: Please share your experience with heat-related illness.
Heat-Related Illness - Symptoms Question: What were your symptoms associated with a heat-related illness?
Heat-Related Illness - Heat Exhaustion Symptoms Question: What were your symptoms of heat exhaustion, and what was the treatment?