NYC Summer 2023: How to protect your heart in the heat

According to the National Weather Service (the National Oceanic and Atmospheric Administration), a heat wave is defined as at least three consecutive days with temperatures of at least 90 degrees Fahrenheit. With temperatures forecasted to reach 90 degrees and above from today, Wednesday, July 26 through Saturday, July 29, now it is a great time to discuss the risk that prolonged heat exposure can have on your heart health.

Just this week, the American Heart Association’s flagship journal Circulation published a study that indicates that the combination of soaring heat and pollution may double the risk for heart attack death. This was according to research of more than 202,000 heart attack deaths in China.

“Extreme temperature events are becoming more frequent, longer and more intense, and their adverse health effects have drawn growing concern. Another environmental issue worldwide is the presence of fine particulate matter in the air, which may interact synergistically with extreme temperatures to adversely affect cardiovascular health,” said senior author Yuewei Liu, M.D., Ph.D., an associate professor of epidemiology in the School of Public Health at Sun Yat-sen University in Guangzhou, China. “However, it remains unknown if and how co-exposure to extreme temperatures and fine particulate pollution might interact to trigger a greater risk of death from heart attack, which is an acute response potentially brought on by an acute scenario and a great public health challenge due to its substantial disease burden worldwide.”

You can read more about that study here.

Every summer, the American Heart Association urges people to take extra steps to protect their heart. We especially want to remind more vulnerable groups to take precautions, such as older adults and people with high blood pressure, obesity or a history of heart disease and stroke.

Temperatures exceeding 100°F or even temperatures in the 80s with high humidity can cause a dangerous heat index that can be hard on the heart. Heat and dehydration cause the heart to work harder, trying to cool itself by shifting blood from major organs to underneath the skin. This shift causes the heart to pump more blood, putting it under significantly more stress. Hydration helps the heart more easily pump blood through the blood vessels to the muscles and it helps the muscles work efficiently.

A report from Kuwait University published in March 2020 found that when temperatures reach extremes of an average daily temperature of 109 degrees Fahrenheit, the number of deaths from cardiovascular disease may double or triple. While the mercury is not expected to soar that high this week, it may benefit New Yorkers to be cautious because another research study, featured at the American Stroke Association’s International Stroke Conference 2019, suggests that the more temperatures fluctuate during the summer, the more severe strokes may become.

“While heat-related deaths and illnesses are preventable, more than 600 people in the United States are killed by extreme heat every year, according to the U.S. Centers for Disease Control and Prevention. If you have heart disease or have had a stroke or you’re older than 50 or overweight, it’s extremely important to take special precautions in the heat to protect your health,” said Donald M. Lloyd-Jones, M.D., Sc.M., FAHA, former president of the American Heart Association and chair of the department of preventive medicine, the Eileen M. Foell Professor of Heart Research and professor of preventive medicine, medicine and pediatrics at Northwestern University’s Feinberg School of Medicine in Chicago.

Medical experts also recommend that people who take medications become aware of how their body may react to extreme heat.

“Some medications like angiotensin receptor blockers (ARBs), angiotensin-converting enzyme (ACE) inhibitors, beta blockers, calcium channel blockers and diuretics, which affect blood pressure responses or deplete the body of sodium, can exaggerate the body’s response to heat and cause you to feel ill in extreme heat. But don’t stop taking your medicines. Learn how to keep cool and talk to your doctor about any concerns,” Dr. Lloyd-Jones says.

The American Heart Association suggests that everyone follows these top 5 hot weather precautions:

Watch the clock: It’s best to avoid the outdoors in the early afternoon (about noon to 3 p.m.) because the sun is usually at its strongest, putting you at higher risk for heat-related illnesses.

Dress for the heat: Wear lightweight, light-colored clothing in breathable fabrics such as cotton, or a newer fabric that repels sweat. Add a hat and sunglasses. Before you get started, apply a water-resistant sunscreen with at least SPF 15, and reapply it every two hours.

Drink up: Stay hydrated by drinking a few cups of water before, during and after going outside or exercising. Avoid caffeinated or alcoholic beverages.

Take regular breaks: Find some shade or a cool place, stop for a few minutes, hydrate and start again

Follow the doctor’s orders: Continue to take all medications as prescribed.

It’s important to know the signs and symptoms when you may be experiencing too much heat.

Symptoms of heat exhaustion:

  • headaches
  • heavy sweating
  • cold, moist skin, chills
  • dizziness or fainting (syncope)
  • a weak and rapid pulse
  • muscle cramps
  • fast, shallow breathing
  • nausea, vomiting or both

If you experience these symptoms, move to a cooler place, stop exercising and cool down immediately by dousing yourself with cold water and re-hydrating. You may need to seek medical attention.

If you experience symptoms of a heat stroke, call 9-1-1 and medical attention right away.

Symptoms of heat stroke:

  • warm, dry skin with no sweating
  • strong and rapid pulse
  • confusion and/or unconsciousness
  • high fever
  • throbbing headaches
  • nausea, vomiting or both

Heat stroke is not the same as a stroke. Stroke happens when a blood vessel to the brain either bursts or is blocked by a clot, causing a decrease in oxygen flow to the brain.

While taking precautions is key, it’s still important to find ways for the whole family to stay active in the heat of summer. Try walking, swimming, biking, skating, jumping rope, building a backyard obstacle course, or organizing a neighborhood soccer game. Even gardening, pushing a stroller or walking the dog counts. Adjusting your activity time to early morning or later in the evening can also help. If being outside is just too much on some days, find indoor locations where you can be active, such as a shopping mall, gym or community recreation center.

It’s also important to keep cool as you refuel. Try light, healthy pre- and post-workout snacks that can also help you stay cool, such as:

  • Chilled or frozen fruit
  • Homemade popsicles made from 100 percent fruit juice
  • Fruit smoothies
  • Cold salads loaded with vegetables, beans, legumes and heart-healthy fish like albacore tuna or salmon
  • Crisp, chilled raw veggies like cucumber, carrot or celery with a light, cool dip
  • Cold sparkling water with a splash of 100% fruit juice or slices of citrus or cucumber

According to NYC Department of Emergency Management, extreme heat is one of the most significant hazards facing New York City, and New Yorkers are especially vulnerable to extreme heat-related hazards during the summer months. Generally, extreme heat means temperatures that hover 10 degrees or more above the average high temperature, last for prolonged periods of time, and are accompanied by high humidity.

Because NYC is made up of materials like asphalt, concrete, and metal that trap heat, temperatures in NYC can oftentimes be 10 degrees higher than other surrounding areas.

Extreme heat can be deadly!

Here are some tips and local resources to help protect your heart in the heat:

  • Stay Informed and Connected

Listen to local weather forecasts and announcements from officials. NYC Emergency Management will send emergency alerts and updates to New Yorkers through various channels, including NotifyNYC, the City’s official, free emergency communications program. Learn more and sign up for Notify NYC at


  • Help Your Neighbors, Protect Your Pets

In New York City, most heat-related deaths occur after exposure to heat in homes without air conditioners. Air conditioning is the best way to stay safe and healthy when it is hot outside, but some vulnerable people do not have an air conditioner or do not turn it on when they need it. Encourage vulnerable family, friends, and neighbors to use air conditioning.

  • Never leave pets (or children) in the car. Temperatures rise quickly even with the windows down and can be deadly for your pet (or child). Call 911 if you see a pet or child in a hot car.
  • Be sure your pets and service animals have access to plenty of water and food, especially when it’s hot.
  • Make sure your pet has plenty of shady places to go when outdoors.
  • Avoid exercising with your pet outside on extremely hot days.

Stay Cool at a Cooling Center

During heat emergencies, the City will open cooling centers throughout the five boroughs. Visit the Cooling Center Finder or call 311 (212-639-9675 for Video Relay Service, or TTY: 212-504-4115) to find out whether a cooling center is open near you.