Heat is a potentially deadly problem—nearly 400 Americans die from heat waves each year. Most of them are elderly people who often don’t realize when they are overheating and in danger.

Part of the problem lies in the fact that older people simply can’t handle the heat as well as younger ones, because they don’t sweat as effectively and have poorer circulation. Obesity, heart disease, dementia, diabetes and other chronic medical conditions can compound the risk. So can certain medications, especially diuretics or those prescribed for hypertension and Parkinson’s disease.

To protect seniors, the standard advice is to get them into an air-conditioned building; have them dress lightly; and keep themselves hydrated.

But this is easier said than done, since poorer circulation also makes many seniors feel too cold in air conditioned spaces and want to reach for a sweater, even when it’s hot out. And some seniors prefer other kinds of drinks to water, even though they may be too sugary for their sedentary lifestyles or filled with caffeine, which is dehydrating.

Lisa Clark, a Dallas physician who specializes in geriatric medicine, told AgingCare.com that caregivers should stay on the alert for signs of confusion or altered mental states in seniors who are out in hot weather, as it could be a sign of heat stroke. If the elderly person should collapse or pass out, “it’s a medical emergency,” Dr. Clark said, and 911 should be called immediately. While you are waiting for help, remove as much clothing as possible and pour cold water all over the elderly person’s body. Should your relative come to, have a cold drink ready, as hydration is critical.

Here are some other tips to protect seniors from the heat:

--If elderly relatives complain of the cold indoors, turn up the air conditioning a bit. If they won’t stay inside, have them sit on a shady porch under a ceiling fan or near a box fan.

--To keep the house cooler without running the air conditioning, close curtains or blinds on the east side of the home during the morning, and the west side in the afternoon.

--If the elderly person doesn’t have air conditioning or refuses to use it in a heat wave, make sure they spend at least some time in a cool air-conditioned space like a mall or theater. “Even two or three hours a day can help,” Dr. Clark said.

--Offer plenty of drinks that seniors prefer, but stay away from iced coffee and other highly caffeinated drinks, or sodas loaded with sodium, which is bad for heart health. Do not serve alcohol, which is dehydrating.

--Keep frozen treats available that have a high water and low sugar content, like sugar-free Popsicles (you can make your own using juice). Or serve fruit with a high water content, like watermelon.

--Seniors sometimes dress inappropriately for warm weather, so make sure that their clothing is lightweight, not form-fitting and light in color. Hats are useful, but make sure that they are loosely woven or ventilated so they don’t trap heat and broad-brimmed so they shade the entire face.