How to stay heart healthy in the heat

The University of Kentucky Public Relations and Strategic Communications Office provides a weekly health column available for use and reprint by news media. This week's column is by Vincent Sorrell, M.D., chief of cardiology at UK HealthCare’s Gill Heart & Vascular Institute.

LEXINGTON, Ky. (May 30, 2023) — Memorial Day marks the unofficial start to summer. From outdoor barbecues to lounging by the pool, summertime means more time spent outdoors with friends and family. But fun in the sun comes with risks.

Humans regulate heat through blood flow. A healthy heart dissipates heat by pushing blood toward the skin. We also shed heat through sweat. People with pre-existing heart conditions are especially at risk, as heat can put extra stress on the heart. According to the Centers for Disease Control and Prevention, more than 600 people die every year from preventable, heat-related illnesses. More than 65,000 are treated in the emergency room for heat stroke, heat exhaustion and dehydration.

It’s important to recognize the signs of heat exhaustion and heat stroke and what to do is someone is in danger. With heat exhaustion, look for signs such as heavy sweating, paleness, muscle cramps, fatigue, and dizziness or fainting. It can be treated by moving the person indoors and cooling them off with a cool cloth. If they don’t improve in an hour, seek medical help.

Heat stroke is more severe. Symptoms include high body temperature (above 103º F), skin that’s red and hot but not sweaty, rapid pulse, throbbing headache, and dizziness and confusion. Heat stroke is a medical emergency — call 911 right away if you see someone in distress.

Dehydration can begin within just a few hours of the onset of extreme heat. Signs of dehydration include fatigue, headache, muscle cramps, dizziness and dry mouth. Dehydration causes the heart to pump harder, which can put heart patients at further risk. Elderly patients in particular need to drink up, as they may not feel thirsty until they are dehydrated. Some patients may still not feel thirsty even after they become dehydrated.

Here are some ways you can stay safe in the sun:

Drink lots of water. Hydration helps the heart pump more easily and helps the muscles work more efficiently. The more you sweat, the more you need to replenish fluids. Skip the alcohol, coffee and tea as it can further dehydrate you. It’s important to keep drinking, even if you don’t feel thirsty.

Keep your cool. In excessively hot temperatures, stay indoors. If you must be outside, find a shady spot and use a fan or a damp towel to stay cool. At the peak of heat in the early afternoon, avoid being outside for prolonged periods of time. Wear loose, light-colored clothing as well as a hat.

Monitor medications. Due to the extra strain of heat, heart patients need to be diligent in keeping up their prescription regime.

Be smart when it comes to exercise. Exercise is important for long-term heart health. If you don’t have the option to take your work out indoors, stick to the early hours of the day. Take it easy — avoid excessive or intense effort in extreme heat.