As summer temperatures soar across the United States, the American Heart Association is alerting the public that extreme heat poses a serious threat to cardiovascular health. According to the National Weather Service, extreme heat is the leading weather-related cause of death in the country, surpassing hurricanes and tornadoes in annual fatalities. A study published in the Journal of the American Medical Association reported that more than 2,300 people died from heat exposure in the U.S. in 2023, and research in the American Heart Association's journal Circulation projects that heat-related cardiovascular deaths could more than double in the coming decades.
“Heat forces the heart to work harder,” said Dr. Manesh R. Patel, volunteer president of the American Heart Association and chief of cardiology at Duke Health. “When your body is trying to cool down, your heart rate increases and your blood vessels expand. For people with heart disease, and even those who are otherwise healthy, that added strain can become dangerous quickly.” The body's cooling mechanism—sweating—leads to fluid loss and dehydration, while the heart must pump more blood to regulate temperature, placing significant stress on the cardiovascular system.
To protect against heat-related heart issues, the American Heart Association recommends limiting outdoor activity between noon and 3 p.m., when temperatures peak. Wearing lightweight, light-colored clothing, a hat, and sunglasses, along with sunscreen, can help. Staying hydrated by drinking water before, during, and after outdoor time is crucial, while avoiding alcohol and caffeinated drinks that promote dehydration. Taking breaks in shade or air-conditioned spaces allows the body to recover.
Recognizing warning signs of heat exhaustion—such as headache, cool pale clammy skin, fast weak pulse, dizziness, weakness, nausea, or vomiting—is vital. If symptoms occur, individuals should move to a cooler place, cool down with cold water, and rehydrate, seeking medical attention if necessary. Heat stroke is a medical emergency requiring immediate 9-1-1 calls; signs include body temperature above 103°F, hot red dry or damp skin, rapid strong pulse, confusion, or loss of consciousness.
Physical activity remains essential for heart health even in summer, but the association advises shifting exercise to early morning or evening hours or moving workouts indoors to air-conditioned spaces. Activities like walking, swimming, biking, or gardening are beneficial but should be done during cooler times. For more information on staying heart-healthy in heat, visit heart.org. Additional resources are available on the release link.
