Heat Too Hot to Handle

By Nina Sherak and Jill Ross, HealthAtoZ contributing writers

How hot is it? It's so hot that your antiperspirant stops working the minute you step out of the house, your clothes stick to you and suddenly the air-conditioner and water cooler become your best friends.

With hot summer weather, most of us feel lethargic and sweaty but still cope. Yet, when a heat wave hits, cooling off is more difficult and many people run the risk of dehydration and heat-related illnesses.

Those at greatest risk for heat-related illness include infants and children up to four years of age, people 65 years of age and older, people who are overweight, and people who are ill or on certain medications, according to the Centers for Disease Control and Prevention (CDC).

You don't have to be a fine-tuned athlete or fragile couch potato to be at risk for a heat-related problem. If exposure to high temperatures is prolonged or there is a problem keeping your core temperature cool, then you are at risk for a heat-related illness such as heat cramps, heat exhaustion or heatstroke.

Overheating is a serious danger and soaring temperatures take their toll. About 240 people in the United States die from heat illnesses each year, according to the CDC. In years with bad heat waves, many more - even thousands - can die.

Experts call it a "heat wave" when there has been more than 48 hours of high heat (90 degrees F or higher) and high humidity (80 percent relative humidity or higher).

How our natural cooling system works

Normally, the body stays cool by letting heat escape through the skin and by evaporating sweat (perspiration), which helps cool the skin and the body core. But in humid weather, sweat doesn't work as well. The surrounding air is already warm and heavy with humidity, and it cannot absorb extra heat and sweat. So the body begins to warm up, and the heart begins pumping more blood to the skin to release the extra heat. You'll notice that even if you sit still in hot weather, your heart beats fast.

People suffer heat-related illness when their bodies are unable to compensate and properly cool themselves. In high temperatures, air is not enough to cool the body down. Either cool water or a cool environment is needed.

Many people think electric fans are sufficient during extreme heat. Fans may provide comfort, but they will not prevent heat-related illness when the temperature is in the high 90s.

The first line of defense against one of the most common types of heat hazards - dehydration - is to drink plenty of fluids. Drink before you get thirsty because by the time you are thirsty, you are already dehydrated. Avoid drinks with caffeine, alcohol or carbonation.

But what happens when heat levels become extreme?

The American Red Cross suggests the following tips to avoid a heat-related illness:

• Slow down. Avoid strenuous activity. If you must do strenuous activity, do it during the coolest part of the day, which is usually in the morning between 4:00 a.m. and 7:00 a.m.
• Stay indoors as much as possible. If air conditioning is not available, stay on the lowest floor, out of direct sunlight. Try to go to a public building with air conditioning each day for several hours.
• Wear lightweight, light-colored clothing. Light colors will reflect the sun's energy.
• Drink plenty of water regularly and often, even if you do not feel thirsty.
• Water is the safest liquid to drink during heat emergencies. Avoid drinks with alcohol or caffeine in them.
• Eat small meals and eat more often. Avoid foods that are high in protein, which increase metabolic heat.
• Avoid using salt tablets unless directed to do so by a physician.
• Make sure your pets get plenty of water as well.

Heat Cramps

Heat cramps are muscular pains and spasms because of heavy sweating from exertion, such as work or exercise, in hot, humid weather. These painful spasms typically last one to three minutes and most commonly occur in the stomach or leg muscles. They usually begin after you've stopped exercising. It generally is thought that the loss of water and salt from heavy sweating causes heat cramps.

What to do about heat cramps:

• Stop activity, and rest in a cool place.



• If fully awake and alert, drink small amounts of cool water or a commercial sports drink.



• Eat salty foods, such as potato chips, salted nuts or popcorn.



• Gently stretch the cramped muscle and hold the stretch for about 20 seconds; then gently massage the muscle.



• Repeat these steps if necessary.

Heat-related Illnesses

Heat-related illnesses are caused by over-exposure to heat. They can be life-threatening. Knowing the early warning signs of a heat-related illness is important, according to the CDC. Remember to keep a keen eye on small children, the elderly, and those who may be in frail health.

Following are the signs of heat exhaustion:

• Skin appears to be cool, moist, pale (the skin may be red right after physical activity); skin may or may not feel hot.
• Headache or dizziness.
• Weakness in the limbs or physical exhaustion.
• Nausea is a common sign.

Following are signs of heat stroke, a more severe form of heat-related illness:

• Skin may still be moist or they may stop sweating and the skin may be red, hot and dry
• Decreased level of alertness or loss of consciousness
• Rapid or weak pulse
• Rapid or shallow breathing pattern
• Vomiting is a clear signal of an emergency
• A high body temperature (sometimes as high as 105 degrees) is an extremely dangerous sign.

What to do for heat exhaustion or heat stroke:

• Get the person out of the heat. Move the person to the shade or a cooler environment.
• Loosen any tight clothing.
• Apply cool, wet cloths, such as towels or sheets, taking care to periodically remoisten the cloths.
• Spraying the person with water and fanning them is also beneficial.
• If the person is conscious, give him or her small amounts of cool water to drink (about 4 ounces every 15 minutes).
• Let the person rest in a comfortable position and watch carefully for changes in his or her condition.
• Refusing water, vomiting and changes in consciousness mean that the person's condition is getting worse.
• If a person exhibits any signs of a serious heat-related illness it is important to call 911 or the local emergency number or seek immediate medical attention.

Related Articles Summertime Survival Guide Making Sense of Sunscreen

External Sources Centers for Disease Control and Prevention Food and Drug Administration The American Red Cross. American Red Cross urges caution during extreme heat. Accessed May 22, 2007. National Institutes of Health

This article was reviewed and updated June 2007.

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