It’s hot out there, and if you’re spending time outside, sunburn shouldn’t be your only concern: it’s important to think about heart health during the heat and humidity, too.
Steamy weather can be dangerous for older individuals, people with heart disease and those taking certain medications for conditions such as high blood pressure and depression, experts say. It can even be a risk for otherwise healthy people if they don’t take some precautions. “Anybody, including athletes, can be vulnerable,” says Dr. Erin Michos, associate director of preventive cardiology and associate professor of medicine at the Ciccarone Center for the Prevention of Heart Disease at the Johns Hopkins University School of Medicine. “Take things slower in the heat. It doesn’t mean you’re less fit.”
Hearts Disease in the Heat
On hot, sticky days, our hearts need to pump harder to initiate the sweating response that cools the body. For people who already have a weakened heart, that extra pumping can cause stress on the cardiovascular system. The worst effects occur during heat waves. For example, 700 deaths were attributed to a 1995 heat wave in Chicago, with 39 percent of the deceased having prior heart conditions, according to a study published by the National Center for Biotechnology Information, part of the National Institutes of Health. And during Europe’s heat wave in 2003, people with cardiovascular disease had mortality rates 30 percent higher than when the weather was not as extreme, according to a study in the Canadian Medical Association Journal.
“Hot weather and heart disease can be a dangerous combination,” Michos says. “People who have a weakened heart have trouble adapting.”
If a heart has been damaged from a heart attack, it might not be able to pump enough blood to cool the body. This is especially true if arteries are narrowed by cholesterol and plaque, which would limit blood flow to the skin and inhibit sweating.
[See: 8 Ways to Stay Hydrated This Summer Without Drinking Water.]
The Elderly and Heat
As people age, their ability to regulate their core temperature can become compromised. Heat exhaustion occurs when a person’s body fails to cool itself, causing symptoms such as fatigue, nausea, headache, dizziness, muscle twitching and confusion. If those symptoms progress, they can lead to heat stroke, which means a person’s core temperature rises above 104 degrees, causing complications to the central nervous system. At that point, organs can start to fail. It’s a medical emergency.
With age, plaque often begins to build up in the arteries, causing them to become more stiff. Plus, the elderly may not feel as thirsty in the heat, and they may not recognize signs they need to hydrate.
During heat exhaustion, blood pressure drops, which can be dangerous because it can cause people to become unsteady and even to fall or faint.
Medications
People who are on medications for high blood pressure or heart disease need to be extra careful in the heat because those drugs can cause the body to have an outsized reaction to hot weather.
Some can cause photosensitivity, or a negative skin reaction to sunlight. Other medications are diuretics, or water pills, that help flush the system but also can promote dehydration. Other classes of drugs that affect the regulatory systems, such as antihistamines and antidepressants, can make people vulnerable, too. “In the summer, people can feel more unwell if they’re on certain medications,” says Dr. Malissa J. Wood, co-director of the Corrigan Women’s Heart Health Program at the Massachusetts General Hospital Heart Center and assistant professor of medicine at Harvard Medical School. The majority of people over 65 years old are on blood pressure medicine, Wood says.
[See: Summer Workouts: How to Handle the Heat.]
Dehydration
Dehydration, which occurs when the body does not have enough fluid, is one of the main causes of heat exhaustion and heat stroke. This causes blood volume to drop, meaning the heart cannot fill properly and pump blood to the body’s organs. In extreme cases, organs will not have enough blood to function properly.
In very serious cases of dehydration, a person would need to get fluids intravenously. Mild dehydration — characterized by thirst and depleted energy — is common and can be reversed by drinking fluids. “In 95, 100 degree heat, we all lose more fluid,” Wood says. “People don’t recognize they are losing fluid through breathing, even if they’re just sitting by the pool. Your breath has droplets of fluid. The air takes away fluid from the skin.”
With outdoor exercise, such as bike riding or gardening, people lose large amounts of fluid fast. “If you exercise, you’ll lose an excessive amount of volume,” Wood says. “If you’re exercising over 30 minutes, take water with you. Drink water, or water with electrolytes.”
It’s important to replenish sodium, potassium, magnesium and other electrolytes to maintain healthy muscles and organs. Electrolytes aid bodily functions such as regulating your heart beat and helping your muscles contract.
When they’re low, and when the body doesn’t have enough fluid, it becomes taxed. “The cardiovascular system is in more stress,” Wood says. “The heart and blood vessels are in more stress.”
Tips to Stay Heart-Healthy in the Heat
Drink. Being proactive and drinking water is important. Drink to thirst; don’t excessively gulp fluids. Avoid too much caffeine and alcohol. Colorless or light yellow urine is a sign you’re properly hydrated.
Dress for the heat. Light-weight clothes, light colors, breathable fabrics and a hat to shield the sun are all appropriate.
Stay inside during peak sun hours, 10 a.m. to 4 p.m. Exercise early in the morning or in the evening, and bring a friend for safety. You can also work out indoors on a treadmill or stationary bike.
Take it easy. If you do exercise outside, make your workout a little shorter and slower. “Your heart has to work harder to dissipate the heat. Healthier people are better at adapting, but people should go a little slower during the hot months,” says Michos, who’s a marathon runner. “Take the pace down, and make sure to stay well-hydrated.”
[See: Your Guide to Stylish Sun Protection.]
Overall, Michos says it’s critical to pay attention to what your body is telling you. “You have to listen to your signals,” she says.
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How to Keep Your Heart Healthy in the Summer Heat originally appeared on usnews.com
