Heat: The Silent but Avoidable Killer

WEDNESDAY, July 3, 2002 (HealthDayNews) -- In hot weather, the term "no sweat" isn't the equivalent of a breeze -- it is a sign of danger.

With much of the country sweltering, government health officials today put out a reminder that this is the time of year when heat kills people and that it's important to be alert to the warning signs.

Failure to sweat means that the body's basic control mechanisms have shut down and that immediate steps must be taken to avoid serious problems, says Michael McGeehin, an environmental health expert with the Centers for Disease Control and Prevention. But there are earlier signs of heat-related physical trouble that, if noticed, can save lives.

The CDC's Morbidity and Mortality Weekly Report notes that there are an average of 400 heat-related deaths every year in the United States, but "in years when we have heat waves, we can have 600 or 700 deaths in as little as 10 days," McGeehin says. "We consider that each of these deaths is preventable. An important public health message is that heat can be a big risk to health and life."

According to the National Weather Service, extreme heat kills more people in a given year than any weather phenomenon except for extreme cold -- more than hurricanes, lightning and tornadoes. It also kills more quietly, in part because people tend to treat it more like an inconvenience than a health hazard and in part because many victims die alone at home.

The time to be especially alert is when a heat wave has gone on for several days, McGeehin says. Public health officials still are talking about the 1995 heat wave that killed 500 people in Chicago and another 85 in Milwaukee in less than two weeks.

And the danger is greatest for the youngest and the oldest of us. With children, the problem is mostly physical, because their bodies have not fully developed their defense mechanisms. The elderly have a similar physical problem; their protective mechanisms aren't as good as they once were, but there is a social component to their risk, since "the elderly in urban areas tend to be poor, live alone, and have no access to air conditioning," McGeehin says.

Staying in an air-conditioned room is a simple and effective defense. For those who go out, on business or pleasure, staying in the hot sun for too long is not advisable, McGeehin says. Getting into the shade now and then will help; drinking a lot of nonalcoholic, non-caffeinated beverages is better, and the more the better. Alcohol and caffeine make your body lose moisture.

"People who are exercising should drink more water than they think is reasonable," McGeehin says, because the body can lose water through sweating faster than most people realize.

Sweating very profusely and feeling unusually warm and uncomfortable are early warning signs of trouble. Feeling unusually hot, with body temperature rising, is another. And "if you stop sweating, you should proceed immediately to a cooler environment," McGeehin says. Heat stroke is a medical emergency, so someone should summon help.

Another urgent danger sign is a deterioration of mental functioning. If you or a companion start to act confused or start talking incoherently, immediate medical attention is necessary.

One particularly dangerous combination is a young person, a car, and hot weather. Between July 1, 2000, and June 30, 2001, the report says, 78 children age 14 or under died when they were left in or around parked cars; more than a third of those deaths happened when the child was left in a motor vehicle in hot weather.

Those deaths can happen even when the weather is not unusually hot. "A young child should never be left in a car, no matter what the temperature," McGeehin says. "Every time the sun is out, a car can become very hot very quickly. On an 80-degree day, the temperature inside a car can rise to over 100 degrees in just 10 minutes."

What To Do

Find air conditioning, if even for a brief time. Chicago has suffered its share of crippling blizzards, but the 1995 heat wave was the city's deadliest weather-related disaster. Other cities learned from this experience, and have since set up buildings for people to cool off in heat waves.

If you have elderly friends, family members, or neighbors, check on them -- especially if you know they don't have air conditioners. Fans don't work once the temperatures rise into the 90s and humidity levels are also high.

You can learn more about the dangers of hot weather and how to protect yourself from the National Weather Service or the Centers for Disease Control and Prevention.