Summer 2024 has brought one broiling heat wave after another. During July, multiple states smashed high-temperature records, with some areas exceeding the previous one by as much as 20 degrees.
For most, this heat is uncomfortable – perhaps made slightly more tolerable with precautions like wearing a wide-brimmed hat or sitting under a sun umbrella. But for some, the heat is downright treacherous because it’s hard on the heart.
“It is more dangerous for your heart in the summer,” said cardiologist Dr. Frederick Meine at Novant Health Heart & Vascular Institute – Wilmington Main. Why? Your heart has to work harder in high heat and humidity, he said.
What can you do to help protect your heart when it’s sweltering? Meine explains.
Compassionate care for your whole heart.
How does extreme heat affect the heart?
Studies have shown that as you get hotter, your heart must work much harder, Meine explained. Both your heart rate and heart stroke volume, the amount of blood your heart sends out to the body, increase when heat and humidity rise.
When you get hot, your heart and vascular system regulate your temperature through:
- Vasodilation: Widening of blood vessels near the skin's surface allows more blood to flow, which helps cool your body. The volume of blood flowing in this cooling effort may be up to four times the typical amount.
- Sweating: As the water in sweat evaporates from your skin, it requires heat energy, which cools your body. But this also increases your heart and metabolic rates.
What are the risks of extreme high temperatures on the heart?
Hot weather can be dangerous for people with heart failure, or those on the verge of it.
“When it is hot and humid, your heart is doing more work, and you need to be much more careful about how you exert yourself, and when in the day,” Meine said. The biggest risks to the heart in extreme heat are heart attack and stroke, he continued.
Research suggests the number of deaths from cardiovascular disease (conditions affecting the heart or blood vessels) may double or even triple in extreme heat, the American Heart Association reports. These risks are particularly elevated when extreme heat is combined with high levels of fine particulate pollution, which are associated with fuel combustion, such as particles from car exhaust, factory emissions or wildfires.
When venturing outside, dress for the heat, which should include lightweight, loose clothing, a wide-brimmed hat and sunscreen. Sunburn can cause dehydration and diminish the body’s ability to cool itself.
What action can I take to protect my heart when the temperatures are so hot?
1. Keep exercising, which is key to reduce the risk of heart disease. But do it smartly.
“You need to be smart about how and when you exercise when it’s really hot out,” Meine said. He emphasized that no matter what, it’s important to do “daily routine, regimented exercise — 30 minutes of exercise a day, every day,” regardless of the weather. His recommendations for staying cool include exercising outdoors only in the early morning, switching to an indoor setting, or participating in a water activity like water aerobics.
When venturing outside, dress for the heat, which should include lightweight, loose clothing, a wide-brimmed hat and sunscreen. Sunburn can cause dehydration and diminish the body’s ability to cool itself.