8 Ways to Prevent Afib in Hot Weather

Avoid the outdoors during the afternoon, when the sun’s UV rays are at their strongest, and instead opt to get some fresh air only after the sun goes down or temperatures cool. If you do find yourself needing to be outside during the heat of the day, be sure to wear sunscreen. Sunburn hinders your body’s ability to cool off, according to the Centers for Disease Control and Prevention.

And when you’re indoors, try to spend time in air-conditioned spaces, take a cold shower, or use ice packs to stay cool.

According to the American Heart Association (AHA), staying hydrated helps the heart more easily pump blood to the muscles. But your body loses fluids and blood salts through sweat, the main mechanism through which the human body cools itself. As a result, being in the heat can make you dangerously dehydrated.

“Loss of fluid [and blood salts] can trigger an arrhythmia,” says Smit Vasaiwala, MD, an associate professor of cardiology at the Loyola University Chicago Stritch School of Medicine in Maywood, Illinois, who says that the main risk factor for atrial fibrillation in high heat is dehydration.

According to the Cleveland Clinic, you should try to drink 6 to 12 ounces of water — about half to a little less than a full pint glass — every 10 to 15 minutes that you are outside being active.

“To avoid arrhythmias in the heat, it is important to keep drinking, even if you don’t feel thirsty,” Dr. Vasaiwala says. “And keep water with you when you go outside.”

RELATED: 6 Smart Tips for Staying Hydrated Throughout the Day

Even if you drink plenty of water while spending time outside on summer days, your heart will still need to work harder in hot weather, which can be dangerous, especially if you have an underlying heart condition.

“Increasing the workload of your heart can both trigger atrial fibrillation and increase your risk for congestive heart failure,” Vasaiwala says. In addition to stroke, congestive heart failure is the other common complication of atrial fibrillation, according to the National Heart, Lung, and Blood Institute. Congestive heart failure is a gradual weakening of your heart that may cause fluid to collect in your lungs and legs. So to be on the safe side, stay inside on extremely hot days to avoid the heat as much as possible, says Vasaiwala.

For some people, intense exercise is a main trigger for heart arrhythmia on its own — although getting regular exercise is a key factor in keeping your heart healthy. However, exercising in the heat adds another potentially stressful component. According to the Cleveland Clinic, the strain put on your heart increases with exercise, especially in hot weather. In fact, for every 1 degree Fahrenheit that your body temperature rises, your heart pumps an additional 10 beats per minute. Vasaiwala says that it’s best to fight the urge to spend time outside and to avoid exercising outside on hot days if you have a heart condition.

According to the Mayo Clinic, the combination of high body temperature and dehydration can lead to heat exhaustion, or heatstroke. Symptoms include dizziness, nausea, flushed skin, headache, confusion, slurred speech, dry (not sweaty or slightly sweaty) skin, and a rapid heartbeat. If you have a heart condition like atrial fibrillation, you're at higher risk. One small study found that nearly a quarter of the 50 heatstroke patients examined had an atrial arrhythmia. Wearing thick clothing that doesn’t let out heat can cause your body temperature to rise even more than it otherwise would.

“If you have to be out in hot weather, wear light clothing and avoid the hottest time of the day,” says Vasaiwala, who says that lightweight, breathable clothing is less likely to trap heat against your body.

Alcohol is a diuretic, meaning it causes a person to urinate more frequently, which further increases the risk for dehydration, even if you’re drinking water. For this reason, alcohol can create a heart health risk, especially in hot weather. Alcohol can also affect your body’s ability to regulate your temperature, according to the Mayo Clinic. Drink water when you can and try swapping that beer for a cooling mocktail.

According to Vasaiwala, you should use the buddy system if you have a heart condition like atrial fibrillation and plan to be outside in extreme heat. Make sure the people you are with know the signs of both heat exhaustion and atrial fibrillation, and the proper response. According to the AHA, many heart conditions share the same warning signs, but fluttering and palpitations are hallmarks of afib.

If you start to notice palpitations or the signs of heat exhaustion, get out of the heat, remove your clothing if possible, and cool off with a cool, damp towel and air-conditioning.

However, Vasaiwala says to seek immediate medical treatment if you experience vomiting, chest pain, or shortness of breath.

The heat index takes both temperature and humidity into account, calculating the “feels like” temperature, which may be hotter than the temperature reading alone, according to the National Weather Service. The human body naturally releases sweat when body temperature rises, notes UPMC HealthBeat. Normally, sweat evaporates off the skin, creating a cooling effect. But in humid weather, sweat can’t evaporate as efficiently — or sometimes at all — meaning your body isn’t able to cool itself. You should be cautious when the heat index is above 80 degrees Fahrenheit, according to the National Weather Service. You can find the heat index for your area at Weather.gov.

Additional reporting by Kaitlin Sullivan