There are three categories of heat emergencies, increasing in severity: heat cramps, heat exhaustion, and heatstroke. All three are preventable by taking precautions in hot weather.

The most common causes of heat emergencies are high temperatures or humidity, dehydration, prolonged or excessive exercise, overdressing in hot temperatures, alcohol consumption, medications (particularly diuretics and psychiatric medications), cardiovascular disease, and sweat-gland dysfunction.

Children, the elderly, and obese people are at increased risk of developing heat illness, but anyone can develop heat illness by ignoring warning signs.

Symptoms of Heat Illness

The early symptoms of heat illness are:

• Profuse sweating

• Fatigue

• Thirst

• Muscle cramps

Later symptoms include:

• Dizziness

• Light-headedness

• Headache

• Weakness

• Nausea and vomiting

• Cool, moist skin

• Darkened urine

As heat illness worsens and progresses to heatstroke, the symptoms also include:

• A temperature above 104° Fahrenheit

• Irrational behavior

• Extreme confusion

• Rapid, shallow breathing

• Dry, hot, and red skin

• Weak, rapid heart rate

• Seizures

• Loss of consciousness

• Coma

• Death

First Aid for Heat Illness

For any signs of shock, seizures, or loss of consciousness, call 911 and manage airway, breathing, and circulation and shock. For non-emergency cases of heat illness take the following steps:

• Lay the person down in a cool place and elevate the feet about twelve inches.

• To lower body temperature, apply cool water or cool, wet cloths to the skin, use a fan, and place covered cold packs on the person's neck, groin, and armpits.

• Give the person a half cup of fluids every fifteen minutes, such as Gatorade, or a drink made by mixing a quart of cool water and a teaspoon of salt.

• Massage cramped muscles firmly and gently.

Avoid the following:

• Don't give medications intended for fever, such as aspirin or acetaminophen, as they may be harmful in heat illness.

• Never use alcohol rubs.

• Don't give the person anything to eat or drink if they are vomiting or unconscious.

• Never give salt tablets or liquids that contain alcohol or caffeine, as they interfere with the body's mechanism of controlling internal temperature.

Never underestimate the seriousness of heat illness, particularly in children, the elderly, or injured persons. Seek medical attention for any symptoms that don't improve with intervention.