Heat exhaustion is a severe form of heat illness. It is a medical emergency. Heat exhaustion is caused by the loss of water and electrolytes through sweating.
Common causes of heat exhaustion include:
Hot, sunny, humid weather
Physical exertion, especially in hot, humid weather
Due to impaired thermoregulation, elderly people and infants can get serious heat illness even at rest, if the weather outside is hot and humid, and they are not getting enough cool air.
Some drugs, such as diuretics, antihistamines, beta-blockers, ecstasy, and amphetamines can cause an increase in the risk of heat exhaustion.
Especially during physical exertion, risk factors for heat exhaustion include:
Wearing dark, padded, or insulated clothing; hats; and/or helmets (for example, football pads or turnout gear)
Having a higher percentage of body fat
Dehydration
Fever
Some medications, like beta blockers and antipsychotic medicines
Signs and symptoms
Symptoms of heat exhaustion include nausea, dizziness, irritability, headache, thirst, weakness, high body temperature, excessive sweating, and decreased urine output.
First aid for heat exhaustion includes:
Moving the person to a cool place
Having the patient take off extra layers of clothes
Cooling the patient down by fanning them and putting wet towels on their body
Having them lie down and put their feet up if they are feeling dizzy
Having them drink water or sports drinks – but only if they are awake, not confused nor vomiting
Turning the person on their side if they are vomiting
If a person with heat exhaustion gets medical treatment, Emergency Medical Technicians (EMTs) or doctors and/or nurses may also:
Give them supplemental oxygen
Give them intravenous fluids and electrolytes if they are too confused to drink and/or are vomiting
If untreated, heat exhaustion may progress to heat stroke.