Hotheaded?

Summer fun is back--and so are the high temperatures that can be problematic for older sun worshippers. Warm weather can severely affect us as we age: witness last summer's European heat wave that was linked to at least 20,000 deaths. Whether you're caring for an older relative or noticing that you're a little weary after sun-drenched days, some simple, not always obvious steps can ensure safety in the sun.

A brief physiology lesson helps explain why a heat wave affects older people disproportionately. When a younger body warms up, the blood vessels expand and blood flows to the skin, dissipating heat. With age, blood vessels tend to thicken and stiffen, making them less able to expel heat. Sweating, another key way of giving off heat, also tends to diminish with age and with getting out of shape. "Basically, the elderly are vulnerable to heat both because they have greater difficulty in regulating their core temperature and because increased prevalence of diseases and medicines impair the ability to dissipate heat," says Dr. Samuel Durso, associate professor of geriatrics at Johns Hopkins. "The two in combination can be deadly." (See box.) What's more, older people generally don't feel thirsty until they're already dehydrated. (The exact reason isn't known.)

Heat-related problems can range from relatively mild dehydration and cramps to heat exhaustion (warning signs include fatigue, weakness, nausea and drenching sweats) to heatstroke (flushed and dry skin, headache, rapid pulse and a sudden loss of consciousness). Severe heatstroke can lead to a fever greater than 105F, delirium, seizures and coma; many cases are fatal.

Knowing the symptoms of heat-related problems is helpful whether you're evaluating yourself or an older person--especially one who might have dementia. Fever is a telltale sign, but you won't necessarily want to pop an aspirin to bring it under control. A viral fever and a body overheating work differently, and aspirin won't help a heat-related fever. With older charges, look for changes in behavior, like refusing fluids, decreased urination, hyperactivity or lethargy. A tongue that's dryer than usual or skin that's more leathery looking can also signify heat problems. Gentle rehydration and moving to a cool place should be the first response. If symptoms persist, call a doctor or get to the ER.

Along with drinking fluids, there are other measures to prevent a problem. For example, experts suggest light outdoor exercise, which acclimatizes your body to the hot environment and helps you expel heat more efficiently. When you exercise, do so in the cooler times of the day, at a moderate pace and for less time than usual. And, suggests Julie Main, general manager of the Santa Barbara Athletic Club in California, use a heart-rate monitor to keep at safe stress levels.

The American College of Sports Medicine suggests drinking 17 oz. of water or a sports drink two hours before exercise and then downing more at regular intervals during exercise. At all times, drink enough so that your urine is light in color. Try putting pitchers of water in every room and eating watery foods like watermelon, cucumbers and Popsicles. Avoid caffeine and alcohol (they are diuretics), and if you're on diuretics or a low-sodium diet, ask your doctor whether you should adjust your diet during hotter seasons.