Heat and your heart: What higher temperatures could mean for your cardiovascular health

For people with chronic heart issues, extreme heat can trigger serious health emergencies. High temperatures combined with cardiovascular disease contribute to about a quarter of heat-related deaths each year, a risk that hits close to home as record-breaking temperatures continue to scorch Orange County.

How extreme heat places stress on your heart Hot weather forces your cardiovascular system to work harder, adding stress that can prove dangerous for people with heart disease, high blood pressure or those taking certain medications.

“When your body is trying to cool down in the heat, your heart rate increases, your blood pressure lowers, and you may experience dehydration and a loss of electrolytes. All these factors combined strain your cardiovascular system,” says Dr. Kevin Kheder, a Hoag interventional and structural cardiologist with the Jeffrey M. Carlton Heart & Vascular Institute. “This can increase the chance of heart attacks, heart arrhythmias, or irregular heartbeat, and heart failure.”

Why older adults and heart patients face greater risk As we age, heat becomes a greater threat because the body's ability to sweat, sense thirst and redirect blood flow for cooling can decline. Several medications commonly taken by older adults and heart patients can compound the risk, according to the Centers for Disease Control and Prevention:

Diuretics may lead to fluid and electrolyte loss.

Beta-blockers may limit the heart-rate response that helps the body release heat.

ACE inhibitors, ARBs and calcium channel blockers may contribute to low blood pressure or fluid-balance problems during hot weather.

Anticholinergic drugs, including some antihistamines, can suppress sweating. But this does not mean patients should skip or change their medication when temperatures climb, Dr. Kheder says.

“Stopping cardiovascular medications abruptly can cause serious complications,” he says. “Instead, talk to your doctor about your risks and what precautions you may take when the temperatures rise.”

How to protect your heart in the heat The best way to protect your heart from extreme heat is to limit your exposure. Stay in air-conditioned spaces during the hottest parts of the day, seek shade when you are outside, drink water regularly and wear lightweight, breathable clothing.

“The extreme heat we are facing this summer may require some people to reschedule their outdoor workouts to the early morning or evening,” Dr. Kheder said. “Stay hydrated and stay cool.”

Warning signs you shouldn't ignore: Heat exhaustion Watch for headache, cool or clammy skin, weakness, dizziness, nausea and a fast but weak pulse. If you notice these signs, move to a cooler place, stop activity and hydrate right away.

Heat stroke Heat stroke is a medical emergency. Signs include a body temperature of 103 degrees or higher, hot, red, dry or damp skin, a rapid, strong pulse, confusion, slurred speech and loss of consciousness. Chest discomfort or shortness of breath in someone with heart disease should also prompt urgent attention.

If you suspect someone is suffering from heat stroke, call 911 and begin cooling the person with a wet, cool cloth to the back of the neck, armpits and groin until help arrives.

A few final thoughts… Extreme heat is more than an inconvenience—it can place significant strain on your heart, especially if you have an existing cardiovascular condition. By planning, staying hydrated, avoiding the hottest parts of the day and recognizing early signs of heat-related illness, you can reduce your risk and enjoy summer safely.

Learn more by visiting the Jeffrey M. Carlton Heart & Vascular Institute at Hoag.