Hot temperatures and high humidity can lead to dehydration, which causes the heart to work harder and puts it at risk, according to the American Heart Association (AHA). Staying hydrated makes it easier for the heart to pump blood to your muscles.
"If you're a heart patient, older than 50 or overweight, you might need to take special precautions in the heat," said AHA President Dr. Robert Harrington.
"Certain heart medications like angiotensin receptor blockers [ARBs], angiotensin-converting enzyme [ACE] inhibitors, beta blockers, calcium channel blockers and diuretics, which deplete the body of sodium, can exaggerate the body's response to heat and cause you to feel ill in extreme heat," said Harrington, a cardiologist who heads the Department of Medicine at Stanford University in California.
If you have heat-related concerns about these medications, discuss them with your doctor. Never stop taking medications on your own.
Infants and the elderly are also at increased risk of heat-related problems, but everyone needs to take precautions in extreme heat.
"It is easy to get dehydrated as you may not be aware that you're thirsty," Harrington said in an AHA news release. "If you're going to be outside, it's important to drink water even if you don't think you need it. Drink water before, during and after going outside in hot weather."
Here are some other important hot weather precautions.
- Avoid the outdoors between noon and 3 p.m., when the sun is usually at its strongest. When outside, wear lightweight, light-colored clothing made of breathable fabrics such as cotton, or a newer fabric that repels sweat. Wear a hat and sunglasses. Apply a water-resistant sunscreen with at least SPF 15 every two hours.
- To stay hydrated, drink a few cups of water before, during and after exercise. Avoid caffeine and alcohol. Take regular breaks. Stop for a few minutes in shade or a cool place, hydrate and start again.