HEATSTROKE OR HEAT EXHAUSTION (Sunstroke; Heat)

General Information

DEFINITION--Illness caused by prolonged exposure to hot temperatures, limited fluid intake or failure of temperature regulation mechanisms in the brain.

BODY PARTS INVOLVED--Total body.

SEX OR AGE MOST AFFECTED--All ages, but most common in the elderly.

SIGNS & SYMPTOMS

Heat exhaustion:

• Dizziness, fatigue, faintness, headache.
• Skin that is pale and clammy.
• Pulse rapid and weak.
• Breathing is fast and shallow.
• Muscle cramps.
• Intense thirst.

Heatstroke:

• Often preceded by heat exhaustion and its symptoms.
• Skin that is hot, dry and flushed.
• No sweating.
• High body temperature.
• Rapid heartbeat.
• Confusion.
• Loss of consciousness.

CAUSES

• Heat exhaustion is caused by insufficient water intake, insufficient salt intake and a deficiency in the production of sweat. (Sweat evaporation is what helps to cool the body.)
• Heat stroke is caused by overexposure to extreme heat and a breakdown in the body's heat-regulating mechanisms. The body becomes overheated to a dangerous degree (body temperature can reach 107F).

RISK INCREASES WITH

• General effects of aging.
• Alcohol or other drug abuse.
• Chronic illness, such as diabetes or blood-vessel disease.
• Recent illness involving fluid loss from vomiting or diarrhea.
• Hot, humid weather.
• Working in a hot environment.
• Loss of body fluids from sweating and failure to drink enough replacement fluid.
• Heavy, restrictive clothing.
• Severe fever.

HOW TO PREVENT

• Wear light, loose-fitting clothing in hot weather.
• Drink water often, don't wait until thirsty.
• Drink extra water if you sweat heavily. If urine output decreases, increase your water intake.
• If you become overheated, improve your ventilation. Open a window or use a fan or air conditioner. This promotes sweat evaporation, which cools the skin.
• Acclimate yourself to hot weather.

What To Expect

DIAGNOSTIC MEASURES--

• Your own observation of symptoms.
• Medical history and physical exam by a doctor.
• Laboratory studies of blood and urine to measure electrolyte levels.

APPROPRIATE HEALTH CARE

• Self-care after diagnosis (mild cases).
• Doctor's treatment.
• Hospitalization to lower body temperature and provide intravenous replacement fluids.

POSSIBLE COMPLICATIONS

• Can involve any major organ system (heart, lungs, kidneys, brain).
• Related to duration and intensity of heat, and to speed and effectiveness of treatment.

PROBABLE OUTCOME--Prompt treatment usually brings full recovery in 1 to 2 days.

How To Treat

GENERAL MEASURES--

• If someone with symptoms is very hot and not sweating: Cool the person rapidly. Use a cold-water bath or wrap in wet sheets. Arrange for transportation to the nearest hospital. This is an emergency!
• If someone is faint but sweating: Give the person liquids (water, soft drinks or fruit juice). Don't give salt pills. Arrange for transportation to the hospital, except in mild cases. Call your doctor for advice.

MEDICATION--Medicine usually is not necessary for these disorder.

ACTIVITY--Activity may be resumed as soon as symptoms improve.

DIET--No special diet.

Call Your Doctor If

You have symptoms of heatstroke or heat exhaustion or observe them in someone else. Call immediately! These conditions may be serious or fatal.