What is heatstroke?

Heatstroke is a life-threatening condition in which the body temperature rises rapidly to 104 degrees F (40 degrees C) or higher and the body's heat-regulating mechanism breaks down.

How does it occur?

It usually happens after long exposure to hot temperatures when you're not used to a new climate. It can also be caused by working in an extremely hot environment, a high fever associated with illness, or exercising too strenuously. Overdressing, overeating, and drinking too much alcohol are contributing factors.

What are the symptoms?

Before heatstroke, you may suffer from heat exhaustion. Symptoms of heat exhaustion are:

• confusion

• fatigue

• heavy sweating

• weakness

• faintness

• dark yellow or orange urine.

When your body can no longer keep your temperature normal, heat exhaustion becomes heatstroke. Symptoms of heatstroke are:

• hot, dry skin

• no sweating

• muscle cramps

• flushing

• shallow breathing

• rapid, weak pulse

• body temperature over 104 degrees F (40 degrees C).

How is it diagnosed?

The doctor will review your symptoms and take your blood pressure and temperature. The doctor may also take a sample of your blood and urine for testing.

How is it treated?

Emergency medical treatment is necessary. If you think someone has heatstroke, call 911 or a doctor immediately. In the meantime, give first aid as follows:

• Move the person to a shady area.

• Remove the person's clothing.

• Cover the person with a wet sheet, and keep the sheet wet for cooling from evaporation.

• Fan the person with paper or an electric fan (preferably not cold air).

• Sponge down the body, especially the head, with cool water.

• Continue giving first aid until the rectal temperature drops to 101 degrees F (38.5 degrees C), or until the body feels cool to the touch.

• If the person is conscious, let them sip water, fruit juice, or a soft drink.

How long will the effects last?

Heatstroke is a very serious problem. Depending on your general health and age, the effects can last as long as a day or two. The fever and disturbance of body temperature should be treated as soon as discovered.

People with true heatstroke will need to be hospitalized in most cases.

How can I take care of myself?

• Avoid strenuous activity in hot or humid weather.

• Wear a broad-brimmed hat and light-colored clothing in the summer.

• Take time to get used to a new climate before being very active or staying in the sun.

• Drink plenty of water whenever you spend a lot of time in the sun or in a hot environment.

• Be aware of how your body reacts to intense sun and high temperatures, and plan accordingly.

What can be done to help prevent heatstroke?

• Stay out of the hot sun, limit exposure, and wear a hat if working in intense sun.

• Wear light-colored, loose-fitting clothing in hot weather.

• Drink extra water when you sweat, even if you aren't thirsty.

• Open windows, or use a fan or air conditioner to improve air circulation.

• Limit food intake to small meals, and limit alcohol intake and activity when it is very hot or when you're not used to a hot climate.