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Too darn hot for your heart?

Dress for summer’s heat, and don’t stay outside too long.

Image: Thinkstock

Summer’s heat, humidity, and smog may be tough for people at risk of heart disease.

Late summer is often a time to relax. But those triple-H days—hazy, hot, and humid—can stress your body as well as your heart.

“There’s no question about the connection between hot weather and cardiovascular health,” says Dr. Patrick O’Gara, a cardiologist at Harvard-affiliated Brigham and Women’s Hospital. During a heat wave, death rates rise—and most of the added fatalities are related to heart problems.

Beware of overheating

When the temperature rises, blood vessels near your skin’s surface relax to help radiate away excess heat. Sweating also helps your body cool off, as liquid sweat evaporates to water vapor. But when the humidity reaches 75% or so, the amount of water in the air makes evaporation difficult. Both mechanisms put pressure on your heart, which has to work harder to push blood to the skin. And sweating steals minerals that you need to keep a healthy fluid balance.

If you take certain blood pressure drugs such as diuretics, which rid your body of salt and water, you’re extra vulnerable to drops in blood pressure on hot, humid days, says Dr. O’Gara. “If you take a dose of a diuretic in the morning, then work in the garden without a hat on a hot day, your blood pressure may dip lower than normal, which can make you dizzy and lightheaded,” he says.

Unhealthy air

Summer’s heat also speeds up the chemical reactions that
create air pollution. Exposure to particulate-matter air pollution (mainly from coal-burning power plants and auto emissions) over a few hours or weeks may slightly increase the risk of a heart attack and death. Long-term exposure for months or years is even more harmful. For real-time information about air quality in your area, see, and heed the warnings about staying inside if the air quality is poor, especially if you have heart disease.

To stay safe on hot days:

  • Stay inside during the hottest part of the day. The sun’s rays
    are usually strongest from noon to 3 p.m.

  • Drink plenty of fluids. Water is best; avoid caffeinated and
    alcoholic beverages.

  • Dress for the heat. Wear lightweight, light-colored clothing and a large, floppy hat. Cover any exposed skin with sunscreen.

Dr. O’Gara also advises reviewing your medications with your doctor, who may suggest that you adjust your blood pressure medication dose on days you plan to be outside in the heat. 

Posted by: Dr.Health

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