Hyperthermia in Older Adults

What is hyperthermia?

Hyperthermia is heat-related illness. Older people are at particular risk of hyperthermia. Many of the people who die of heat stroke each year are over 50 years of age. There are 5 levels of heat illness:

• 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. You may feel faint.
• Heat syncope is sudden dizziness 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 after 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. People on salt restricted diets may be at increased risk. However, do not use salt pills without first asking your healthcare provider.
• Heat exhaustion is a warning that the body is getting too hot. You may be thirsty, giddy, weak, uncoordinated, nauseous, and sweating a lot. The body temperature is usually normal and the pulse is normal or raised. The skin is cold and clammy. Heat exhaustion often is caused by the body's loss of water and salt.
• Heat stroke is life-threatening. A person with heat stroke has a body temperature above 104° F. Other symptoms may include confusion, bizarre behavior, fainting, staggering, strong rapid pulse, dry flushed skin, lack of sweating, possible delirium or coma. Heatstroke may damage the kidneys, heart, lungs, muscles, liver, intestines, and brain. Emergency medical treatment is necessary. If you think someone has heatstroke, call 911 immediately.

How does it occur?

Factors that may increase your risk of heat illness include:

• Poor circulation, inefficient sweat glands, and changes in the skin caused by the normal aging process.
• Heart, 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.
• Medicines such as diuretics, sedatives, tranquilizers, and certain heart and blood pressure drugs may decrease your body's ability to cool itself through perspiration.
• Taking several drugs for various conditions. Do not, however, stop taking prescribed medicine until you talk with your healthcare provider.
• Being very overweight or underweight.
• Drinking alcoholic beverages.
• Living in homes without fans or air conditioners.
• Overdressing or wearing the wrong kinds of fabrics for hot weather.
• Not staying indoors on especially hot and humid days, particularly when there is an air pollution alert in effect.

How is it diagnosed?

A person with symptoms including headache, nausea, and fatigue after exposure to heat may have a heat-related illness. Older adults with these symptoms should consult their healthcare providers. Someone with symptoms of heat stroke needs to be treated in a hospital as soon as possible.

How is it treated?

If the victim has signs of heat stroke, dial 911 or call an ambulance right away. Without medical attention heat stroke is often deadly, especially for older people. To help treat heat exhaustion:

• Get the victim out of the sun and into a cool place, preferably one that is air-conditioned.
• Loosen clothing.
• Offer fluids. Water and fruit and vegetable juices are best.
• Encourage the person to shower or bathe, or sponge off with cool water.

What can be done to prevent hyperthermia?

• Drink plenty of liquids, even if you are not thirsty.
• Dress in light-weight, light-colored, loose-fitting clothing. Natural fabrics such as cotton are best.
• Avoid the mid-day heat and do not engage in vigorous activity during the hottest part of the day (12 PM to 4 PM).
• Wear a hat or use an umbrella for shade.
• Open windows at night. Cover windows when they are exposed to direct sunlight. Keep curtains, shades, or blinds drawn during the hottest part of the day. Using a fan to circulate the air will help some. If possible, use air conditioners or visit air-conditioned places such as libraries, shopping malls, and theaters. Air conditioners should be set below 80° F (27° C).
• If you are 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 necessary.
• Ask your healthcare provider whether your medicines increase the risk of hyperthermia.