Summer is in full swing, and much of the country has been seeing record-high temperatures. There is no doubt that those at risk for heart disease need to take extraordinary precautions. 

 “Our bodies are built to self-regulate temperature — to keep us from getting too hot or too cold,” said Dr. Murray Whitaker, cardiologist. “The body has two paths to shed extra heat, radiation and evaporation, both of which put stress on the heart and increase the risk of a cardiac event.”

Radiation requires rerouting blood flow so more of it goes to the skin. This makes the heart beat faster and pump harder. On a hot day, it may circulate two to four times more blood per minute than it does on a cool day.

Every drop of sweat that evaporates from your skin whisks away heat. But evaporation also strains the cardiovascular system. Sweat pulls more than heat from the body — it also pulls out sodium, potassium and other critical minerals. To counter those losses, the body begins secreting hormones that help the body hold onto water and minimize mineral loss. 

Dr. Whitaker continued, “Most healthy people can tolerate these occurrences with little difficulty and minor discomfort. But people with damaged or weakened hearts, the elderly and those who are overweight can have a much harder time coping physically, and need to take precautions against heat stroke or even cardiac arrest.” 

High-risk categories include:

• Prior heart attack. Damage from a heart attack can keep the heart from pumping enough blood to get rid of heat.
• High cholesterol/arterial disease. Cholesterol-narrowed arteries can limit blood flow to the skin. 
• Stroke, Parkinson’s disease, Alzheimer’s disease, diabetes. These and other conditions can dull the brain’s response to dehydration, so it may fail to send thirst signals. Drink water!
• Atrial Fibrillation. The main concern for AFIB in high heat is dehydration, which can trigger arrhythmia. It can also raise the risk of stroke and heart failure. 
• Medications. Certain medications, like beta-blockers, ACE receptor blockers, ACE inhibitors, calcium channel blockers and diuretics, can exaggerate the body’s response to heat. 

It’s important, though, to stay active throughout the warm-weather months. It’s also important to continue taking your medications. The key is taking the proper precautions to stay both active AND safe in the heat. Here are our top five must-do tips for those in the higher-risk categories:

1. Buddy up! This is the most important tip of all. If you have any questions about your health or your tolerance for the heat, always travel, walk, and exercise with a companion. They could be the one to save your life, if anything unexpected occurs.
2. Drink up. Stay consistently hydrated with a few cups of water before, during and after your exercise and/or sun and heat exposure. Avoid caffeinated and alcoholic beverages. 
3. Dress for success. Wear lightweight, light-colored clothing in breathable fabrics such as cotton, or a synthetic fabric that repels sweat. Add a hat in a light color.
4. Right foot forward. Most people sweat most in their shoes, so opt for ventilated shoes and/or socks that repel perspiration. Foot powders and antiperspirants also help manage sweat. 
5. Take regular breaks. High heat is not the time to push your body. Get out of the sun and into the shade every 20-30 minutes, hydrate and evaluate how you feel before starting again.

It’s best to consult with your doctor about your particular fitness for activity in high heat. Most importantly, be mindful of any early symptoms of heat exhaustion or heat stroke. Changes in your body or mental state like headaches, nausea, weakness, confusion, or cool or clammy skin are all signs that your body is not coping well with the heat. Cool down with wet cloths, compresses or ideally, in a cooler, air-conditioned space. If in doubt, don’t risk it – call 9-1-1, especially if you are alone. 

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