Keeping Your Heart on Beat in the Summer Heat
7/28/2025
DeTar Warns Extreme Temperatures Can Put Added Stress on the Heart
With summer in full swing and South Texas once again dealing with triple-digit temperatures, the intense heat can do more than just cause discomfort—it can be dangerous, especially for individuals with heart conditions like atrial fibrillation (AFib), high cholesterol, or heart disease. According to the Texas Department of State Health Services, heat-related illnesses spike each July and August, with older adults and those with chronic conditions at the highest risk. Nationwide, more than 6 million Americans live with AFib, a condition that already increases the risk of stroke and heart failure—and heat can make symptoms worse.
“During hot, humid weather, the heart has to work significantly harder to cool the body by pumping more blood to the skin and producing sweat,” said Dr. Jasvinder Sidhu, cardiac electrophysiologist with DeTar Medical Group. “For those with heart conditions or AFib, that added strain can trigger symptoms such as dizziness, shortness of breath, or even dangerous arrhythmias.”
A key factor: for every 1°F increase in body temperature, heart rate rises by approximately 10 beats per minute, according to the National Institutes of Health. That means extreme heat—especially in the 100°F+ range commonly seen across South Texas—can lead to rapid heart rate changes that are especially risky for those with pre-existing cardiovascular issues.
In addition to the heat itself, many common heart medications can interfere with the body’s ability to manage it. “Beta blockers, diuretics, and certain blood pressure medications can reduce the body’s natural ability to stay cool, increasing the risk of dehydration or heat-related illness,” Dr. Sidhu explained. “But patients should never stop taking their medications without medical advice. Instead, talk with your cardiologist about how to adjust your summer routine to stay safe.”
Tips for Heart Health in the Heat:
- Hydration: Drink water consistently throughout the day. Avoid overhydration, which can affect electrolyte balance.
- Nutrition: Replenish lost sodium, potassium, and magnesium through food or supplements.
- Exercise: Schedule workouts for early morning or evening. Avoid peak heat hours (10 a.m. – 4 p.m.). Indoor activity is safest.
- Clothing: Choose lightweight, moisture-wicking, breathable fabrics that help regulate body temperature.
Dr. Sidhu emphasized the importance of recognizing symptoms of heat-related illness—especially for those with AFib or other heart conditions. Those include: body temperature over 103°F, red, hot, or dry skin, inability to sweat, rapid heartbeat, headache, dizziness, or confusion, nausea or vomiting and/or fainting or disorientation. “If more than one of these symptoms is present, it could be heatstroke—call 911 immediately,” said Dr. Sidhu.
While waiting for emergency responders, Dr. Sidhu advised to move the person to a shaded or air-conditioned area, use cool (not cold) water—via spray, sponge, or damp towel—to help lower body temperature and said to not give fluids if the person is disoriented or unconscious.
DeTar encourages individuals with heart conditions—and those caring for them—to plan ahead during this high-risk season. Stay hydrated, avoid peak heat, dress appropriately, and work with your healthcare provider to develop a personalized summer care plan. “When it comes to your heart, prevention is the best protection,” Dr. Sidhu said. “Pay attention to how your body responds to the heat and take steps to stay safe.”
Back