July 2010
Extreme heat can affect anyone, but you don't have to become a victim.
Most people know that extreme heat can make us sick. But we may think of heat-related illness as something that only affects people who are overdoing it -- like overheated marathon runners, professional athletes, or new recruits doing drills on military bases.
But most people who die from heat stroke in the U.S. -- about 400 every year, and possibly more -- don't get it from overexerting themselves on a muggy day.
Heat stroke occurs when the body is unable to regulate its temperature. The body's temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down.
"People just don't understand the risks of extreme heat," says Michael McGeehin, PhD, MSPH. "They aren't aware how quickly they can get into trouble."
Heat and Disease
In order to work well, the body has to stay at a normal temperature. If it heats up even by a few degrees, your body starts to cool itself. The most obvious and familiar reaction is that you start to sweat. As the hot perspiration evaporates off your skin, you're cooled down.
The body reacts to heat in many other, less obvious ways. For instance, hot temperatures make your heart beat faster. That's not only if you're exercising. Even if you're sitting perfectly still, your heart will be beating harder when you're hot. That's because the heart is working harder to push blood to the skin and muscles. Getting blood closer to the surface of the body gets it to cool down and helps with sweating.
"Anything that interferes with our natural cooling system could lead us to heat exhaustion and heat stroke faster," states McGeehin. "A lot of medical conditions can do that."
When the body can't get rid of excess heat fast enough, the cooling system eventually breaks down, and the organs begin to overheat. If they get hot enough, they'll stop working. Confusion, seizures, permanent disability, and even death can occur if treatment isn't provided. That's heat stroke and it's a medical emergency.
Obesity
Doctors have come to recognize that obesity is a serious health problem in America. It poses a number of risks, including an increased danger of having a heat-related illness. Part of the problem is simple physics. The bigger the person, the harder it is to lose excess heat. The body's natural cooling systems can't work quickly enough. Obesity also puts extra pressure on the heart, so when hot weather requires that the heart beats even harder, it may not be up to the task, Knochel says.
Signs of Heat-Related Illness
It's important to know the signs of trouble. Excessive heat can first cause heat exhaustion -- especially in people who are working or exercising outside. The symptoms include:
-
- Dizziness or fainting
- Heavy sweating
- Muscle cramps
- Cold or clammy skin
- Headaches
- Rapid heartbeat
- Nausea
If you have these symptoms, get out of the heat, drink water, juice or sports drinks (unless your doctor tells you otherwise), and get medical attention.
If it isn't treated, heat exhaustion can lead to heat stroke, which is an emergency. Heat stroke also develops in people who aren't being physically active but are simply in a hot environment. The signs of heat stroke are:
- Rapid heartbeat
- Confusion or delirium
- Warm, dry skin (because the body is no longer able to sweat)
- Fever of greater than 104 degrees
- Severe headaches
- Seizure or muscle twitching
- Unconsciousness
- Death
Remember, heat stroke needs immediate attention. Call 911.
Enjoying the Summer Safely
Although excess heat can certainly cause problems, we're not trying to dissuade people from getting outside and enjoying themselves during the summer. Getting outside and getting some physical activity is good for just about everybody -- with medical conditions or not.
But if you're at higher risk of having problems from the heat because of a medical condition, just take some extra precautions. Remember, you need to get out of the heat sooner than the people around you.
On the whole, someone with a medical condition should follow the same precautions as anyone else on a hot day. To prevent heat-related illnesses:
- Don't go outside during the hottest times of the day.
- Spend time in a cool place. If you don't have air conditioning, go somewhere that does, such as a friend's home, a mall, or a library.
- Drink extra water (unless your doctor tells you otherwise), and avoid alcohol and drinks with caffeine.
- Wear loose-fitting cotton clothes.
- Pay attention to weather reports and try to plan ahead for hot days.
Also, remember to check on older relatives or friends who might be at higher risk of heat-related illness because of medical conditions. Make sure that they're staying cool on hot days.
You may just need to take a few extra precautions to have a healthy and happy summer.