Staying cool is important in the summer heat, and so is looking after your heart health when you have heart disease. Heat and humidity can both negatively affect your heart.
“Heat causes the body to work harder to cool itself, increasing the heart rate and blood flow, which can strain the overall cardiovascular system,” says Rosy Thachil, MD, a Fellow of the American College of Cardiology and director of the cardiac intensive care unit at Elmhurst Hospital Center in Elmhurst, New York.
High temperatures can stress your body, increasing your risk of dehydration, electrolyte imbalances, and blood clots. “Dehydration and heat stress can worsen symptoms in people with preexisting heart disease, raising the risk of complications like arrhythmias or heart attacks,” says Dr. Thachil. But there are many steps you can take to stay safe this summer and manage your condition.
1. Stay Well-Hydrated
Drinking water is especially important when exercising or doing any activities outside in the heat. “Adequate hydration helps reduce the amount of strain on the heart by helping it pump blood more efficiently and helping the body’s muscles function more efficiently,” says Emily Cendrowski, MD, a cardiologist at the BJC Medical Group in St. Louis.
While some health experts typically recommend that women drink about 11.5 cups of water and men drink 15.5 cups every day, you’ll want to drink more if you’re spending lots of time outside or you tend to sweat a lot. Try to drink fluids consistently throughout the day, too, such as before, during, and after activities. If you’re thirsty, you may already be dehydrated.
When it comes to fluids, “water is best to prevent dehydration and heat stress,” says Thachil. Avoid drinking soda or sugary drinks, as these don’t have hydrating benefits. In fact, “caffeinated, sugary, and alcoholic beverages can worsen dehydration,” says Dr. Cendrowski.
In addition to drinking water, eating raw fruits and vegetables can help you stay hydrated throughout the day. They have high water content and electrolytes, which are minerals that can help maintain fluid balance in your body. Examples of hydrating fruits and vegetables include:
Watermelon
Oranges
Strawberries
Cantaloupe
Peaches
Cucumbers
Celery
Lettuce
Tomatoes
2. Avoid Exercising During the Hottest Times of Day
Exercise, in general, can be beneficial for people with heart disease. But exercising during the hottest time of day or during excessive heat comes with risks and should be avoided. “People with heart disease should avoid strenuous activities during the hottest parts of the day, typically between noon and 3 p.m., to minimize complications related to dehydration and overexposure to heat,” says Cendrowski.
Instead, try “light to moderate activities during cooler parts of the day, like the early morning or evening,” says Thachil. These activities may include brisk walking, gardening, or leisurely biking.
Aim to avoid direct sunlight, always keep a water bottle on hand, and take rest breaks in the shade, adds Thachil.
Be sure to discuss your exercise plan with your healthcare provider. They can discuss any potential safety concerns and advise you on what’s best for you and managing your heart disease.
3. Know the Signs and Symptoms of Heat Exhaustion and Heat Stroke
When the temperature rises, so can your risk of heat exhaustion and heat stroke. Both conditions are serious, but they can be prevented.
Heat exhaustion happens when your body overheats. Symptoms include:
Heavy sweating
Having cool skin and goosebumps despite sweating
Feeling faint and fatigued
Having a headache
Experiencing muscle cramps
If not treated quickly, heat exhaustion can lead to heat stroke, which is life-threatening and a medical emergency. Heat stroke is when your body is unable to regulate your temperature, says Cendrowski. Symptoms of heat stroke include:
Confusion or delirium
Dizziness
Feeling fatigued
Seizures
Fast heart rate
Quick, shallow breathing
Nausea and vomiting
Having a body temperature of 103 degrees or more
In general, “watch for chest pain, excessive sweating, dizziness, rapid heartbeat, weakness, or confusion,” says Thachil. “These may suggest heat exhaustion or heat stroke requiring immediate medical attention.”
4. Protect Your Skin
“Skin changes that indicate overexposure to heat include sunburn and heat rash,” says Cendrowski. Sunburn can lead to dehydration,while heat rash can contribute to heat exhaustion.
To prevent a sunburn, wear sunscreen and hats while outside, and try to stay in shady areas, says Laura Sutaria, MD, MPH, a cardiologist at Montefiore Health System in Bronx, New York. “Sunburns can actually make it harder for your body to cool off effectively.”
Wearing lightweight, loose-fitting, and light-colored clothing can aid in sunburn prevention, as well as help regulate your body temperature and protect against heat rash.
You can also try to limit your time outdoors and opt for cooler, indoor environments to prevent heat rash.
5. Avoid the Outdoors When Air Quality Is Bad
“For people with heart disease, it is important to monitor weather forecasts for heat advisories and to stay indoors on those days,” says Cendrowski. When the weather heats up, the air quality can worsen. Fine particulates, such as smoke, dust, and dirt, can build up and make it difficult to breathe.
Air pollution can be especially harmful for people with heart disease, increasing the risk of heart attacks, stroke, and arrhythmias. “Poor air quality can exacerbate heart symptoms by increasing inflammation and reducing oxygen intake,” says Thachil. “Checking forecasts can allow you to plan activities when air pollution and temperature levels are safer.”
Most weather apps and websites will list the day’s air quality score, with a higher score indicating worse air quality. For example, an air quality score above 100 is considered unhealthy for sensitive groups.
6. Cool Down Your Home and Maintain Indoor Air Quality
Throughout the warmer months, aim to “keep indoor temperatures cool, ideally between 70 and 75 degrees F (21 and 24 degrees C), using fans or air conditioning,” says Thachil. “Avoid sudden temperature changes and ensure proper ventilation to reduce heat stress.”
On really hot days, such as when it’s over 90 degrees F, be extra careful when using fans alone to cool down, as they can cause your body temperature to rise. If you don’t have air-conditioning at home, look for cooling centers in your area. Or head to your local library or a shopping center, as these facilities are likely to have air-conditioning.
When avoiding the heat outdoors and staying inside, it’s important to consider indoor air quality, too. Indoor air pollution, such as cigarette smoke and air fresheners, can make it difficult to breathe and may worsen heart disease symptoms. Try to remove these sources as much as possible. Air out your home by opening windows when the outside air quality score is low and temperatures drop, such as in the mornings or evenings. Air purifiers can also remove particulates from the air and improve air quality indoors.
7. Discuss Medication Options With Your Doctor
Certain medications can affect how you respond to heat. “Patients with cardiovascular disease are often on medications, such as diuretics, beta-blockers, and calcium channel blockers, that can make it even more difficult for the body to compensate for temperature extremes,” says Dr. Sutaria.
If you’re taking any of these medications and are having difficulty navigating the heat, Cendrowski advises talking with your doctor “to see if it is appropriate to hold certain medications that increase risk of dehydration and poor response to the heat.”
Your doctor knows your medical history and can discuss with you potential risks and benefits of temporarily stopping these medications. They may be able to offer alternative medications or treatments to help, too.
The Takeaway
High temperatures in the summer months can cause your heart to work harder to cool down your body. The heat can increase your heart rate and risk of dehydration and serious complications like heat stroke.
Staying hydrated, avoiding exercise during the hottest parts of the day, protecting your skin, and checking air quality scores before heading outside can help you safely manage your condition.
Know the signs and symptoms of heat exhaustion and heat stroke, and act quickly if you or someone else begins to experience them. Heat exhaustion can lead to heat stroke, which can be life-threatening.
