If you’re one of the estimated 5.3 million Americans living with atrial fibrillation (afib) — a heart arrhythmia or irregular heartbeat — you may have noticed that the change in seasons affects your condition. Hot weather requires your heart to work harder because of the stress on the body caused by heat, potentially triggering an episode of atrial fibrillation. In addition, extreme heat can raise your risk for stroke and heart failure, two potentially fatal cardiovascular events that can be triggered by an afib attack.
Fortunately, you can adopt a few key habits to keep your heart safe from the heat in warmer months.
1. Protect Your Skin From the Sun
Avoid the outdoors during the afternoon, when the sun’s UV rays are at their strongest, and instead opt to get fresh air only after the sun goes down or temperatures cool. If you need to be outside during the heat of the day, be sure to wear sunscreen, since sunburn hinders your body’s ability to cool off.
When you’re indoors, try to spend time in air-conditioned spaces, take cold showers, and use ice packs to stay cool.
2. Hydrate to Keep Your Heart Rate Regular
Staying hydrated helps the heart more easily pump blood to the muscles, according to the American Heart Association. On the other hand, your body loses fluids and blood salts through sweat, the primary way that the 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 Loyola Medicine in Maywood, Illinois. The main risk factor for atrial fibrillation in high heat is dehydration, Dr. Vasaiwala says. Because of fluid loss through sweat, dehydration can happen in summer heat and humidity, even when you’re drinking your usual amount of water.
To stay hydrated in the heat, 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,” Vasaiwala says. “And keep water with you when you go outside.”
3. Stay Indoors in Extreme Heat and Rest Your Heart
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 a common complication of atrial fibrillation. 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.
4. Avoid Exercising Outside so You Don’t Trigger Afib
For some people, intense exercise is the main trigger for heart arrhythmia on its own — although getting regular exercise is a key factor in keeping your heart healthy. Exercising in the heat adds another potentially stressful component.
The strain put on your heart increases with exercise, especially in hot weather. Your body works to maintain a constant temperature, and as outdoor temperatures rise, your cardiovascular system has to work even harder to keep cool. For every 1 degree F 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.
5. Wear Light Clothing to Keep Body Temps Steady
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 a heart condition like atrial fibrillation, you’re at a higher risk. According to research, during a heat wave, deaths from cardiovascular issues increase by 11.7 percent. People with preexisting heart conditions are especially at risk. “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.
6. Avoid Dehydrating Alcohol
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, especially in hot weather, can create a heart health risk. Alcohol can also affect your body’s ability to regulate your temperature, according to Mayo Clinic. Drink water when you can and try swapping that beer for a cooling mocktail.
7. Buddy Up for Safety in Case Heat Causes Symptoms
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 that the people you are with know the signs of both heat exhaustion and atrial fibrillation, and the proper response. Many heart conditions share the same warning signs, but fluttering (a kind of abnormal heart rhythm) 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.
Vasaiwala says to seek immediate medical treatment if you experience vomiting, chest pain, or shortness of breath.
8. Always Check the Heat Index
The heat index takes both temperature and humidity into account, calculating what the temperature feels like, which may be hotter than the temperature reading alone, according to the National Weather Service. The body naturally releases sweat as its temperature rises. 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 F. You can find the heat index for your area and current extreme heat advisories at Heat.gov.
