Hyperthermia: A Hot Weather Hazard for Older People

Introduction
Warm weather and outdoor activity generally go hand in hand. However, it is important for older people to take action to avoid the severe health problems often caused by hot weather. "Hyperthermia" is the general name given to a variety of heat-related illnesses. The two most common forms of hyperthermia are heat exhaustion and heat stroke. Of the two, heat stroke is especially dangerous and requires immediate medical attention (see Definitions).

What Causes Hyperthermia?
Regardless of extreme weather conditions, the healthy human body keeps a steady temperature of 98.6° F (37° C). In hot weather, or during vigorous activity, the body perspires. As this perspiration evaporates from the skin, the body is cooled. If challenged by long periods of intense heat, the body may lose its ability to respond efficiently. When this occurs, a person can experience hyperthermia.

What Can Be Done to Prevent Hyperthermia?

•Drink plenty of liquids, even if not thirsty.

•Dress in light-weight, light-colored, loose-fitting clothing.

•Avoid the mid-day heat and do not engage in vigorous activity during the hottest part of the day (noon-4 p.m.).

•Wear a hat or use an umbrella for shade.

•If possible, use air conditioners liberally or try to visit air-conditioned places such as libraries, shopping malls, and theaters. For an air conditioner to be beneficial it should be set below 80° F.

•If not used to the heat, get accustomed to it slowly by exposing yourself to it briefly at first and increasing the time little by little.

•Avoid hot, heavy meals. Do a minimum of cooking and use an oven only when absolutely necessary.

•Ask your physician whether you are at particular risk because of medication.

Health and Lifestyle Risk Factors

The temperature does not have to hit 100° for a person to be at risk. Both one's general health and/or lifestyle may increase a person's chance of suffering a heat-related illness.

Health Factors That May Increase Risk

•Poor circulation, inefficient sweat glands, and changes in the skin caused by the normal aging process.

•Heat, lung, and kidney diseases, as well as any illness that causes general weakness or fever.

•High blood pressure or other conditions that require changes in diet. For example, people on salt restricted diets may increase their risk. However, salt pills should not be used without first asking a doctor.

•The inability to perspire, caused by medications including diuretics, sedatives and tranquilizers, and certain heart and blood pressure drugs.

•Taking several drugs for various conditions. It is important, however, to continue to take prescribed medication and discuss possible problems with a physician.

•Being substantially overweight or underweight.

•Drinking alcoholic beverages.

Lifestyle Factors That Can Increase Risk

Unbearably Hot Living Quarters. People who live in homes without fans or air conditioners should take the following steps to reduce heat discomfort: open windows at night; create cross-ventilation by opening windows on two sides of the building; cover windows when they are exposed to direct sunlight; and keep curtains, shades, or blinds drawn during the hottest part of the day.

Lack of Transportation. People without fans or air conditioners often are unable to go to shopping malls, movie houses, and libraries because of illness and/or the lack of transportation. Friends or relatives might be asked to supply transportation on particularly hot days. Many communities, area agencies, religious groups, and senior citizen centers provide such services.

Overdressing. Because they may not feel the heat, older people may not dress appropriately in hot weather. Perhaps a friend or family member can help to select proper clothing. Natural fabrics such as cotton are best.
Visiting Overcrowded Places. Trips should be scheduled during non-rush hour times and participation in special events should be carefully planned.
Not Understanding Weather Conditions. Older people, particularly those at special risk (see health factors), should stay indoors on especially hot and humid days, particularly when there is an air pollution alert in effect.

How is Hyperthermia Treated?
If the victim is exhibiting signs of heat stroke, seek emergency assistance immediately. Without medical attention heat stroke is frequently deadly, especially for older people.

Heat Exhaustion May Be Treated in Several Ways

•Get the victim out of the sun and into a cool place—preferably one that is air conditioned.

•Offer fluids but avoid alcohol and caffeine. Water and fruit and vegetable juices are best.

•Encourage the individual to shower or bathe, or sponge off with cool water.

•Urge the person to lie down and rest, preferably in a cool place.

How is Hyperthermia Detected?
A person with symptoms including headache, nausea, and fatigue after exposure to heat probably has some measure of a heat-related illness. It is important to recognize the difference between the very serious condition known as heat stroke and other heat-related illnesses. Persons experiencing any of these symptoms should consult a doctor.

Definitions
Heat stress occurs when a strain is placed on the body as a result of hot weather.
Heat fatigue is a feeling of weakness brought on by high outdoor temperature. Symptoms include cool, moist skin and a weakened pulse. The person may feel faint.
Heat syncope is sudden dizziness experienced after exercising in the heat. The skin appears pale and sweaty but is generally moist and cool. The pulse may be weakened, and the heart rate is usually rapid. Body temperature is normal.
Heat cramps are painful muscle spasms in the abdomen, arms, or legs following strenuous activity. The skin is usually moist and cool and the pulse is normal or slightly raised. Body temperature is mostly normal. Heat cramps often are caused by a lack of salt in the body, but salt replacement should not be considered without advice from a physician.
Heat exhaustion is a warning that the body is getting too hot. The person may be thirsty, giddy, weak, uncoordinated, nauseous, and sweating profusely. The body temperature is usually normal and the pulse is normal or raised. The skin is cold and clammy. Although heat exhaustion often is caused by the body's loss of water and salt, salt supplements should only be taken with advice from a doctor.
Heat stroke can be LIFE-THREATENING! Victims of heat stroke almost always die so immediate medical attention is essential when problems first begin. A person with heat stroke has a body temperature above 104° F. Other symptoms may include confusion, combativeness, bizarre behavior, faintness, staggering, strong rapid pulse, dry flushed skin, lack of sweating, possible delirium or coma.

Heat-related illnesses can become serious if preventative steps are not taken. It is important to realize that older people are at particular risk of hyperthermia. Many people die of heat stroke each year; most are over 50 years of age. With good, sound judgment and knowledge of preventive measures the summer can remain safe and enjoyable for everyone.