Heat exhaustion occurs when a person can't sweat enough to cool the
body. It generally develops when a person is working or exercising in hot
weather, sweats a lot, and does not drink enough liquids to replace those lost
fluids. Heat exhaustion can be caused by loss of fluid (dehydration) or loss of
Symptoms of heat exhaustion include fatigue, weakness, headache,
dizziness, or nausea, and the skin is pale, cool, and moist. Mild heat
exhaustion does not cause a decrease in a person's mental alertness, but it may
occasionally cause fainting. Mild cases of heat exhaustion usually can be
treated at home.
Moderate to severe heat exhaustion can sometimes lead to
heatstroke, which requires emergency treatment.
Primary Medical Reviewer
William H. Blahd, Jr., MD, FACEP - Emergency Medicine
How this information was developed to help you make better health decisions.