Rising Temperatures Can Put Extra Strain On Your Heart: A Doctor’s Guide To Staying Safe 

By Dr. Joy Shome

During heatwaves, the body exhibits various physiological responses to accommodate itself in extreme environmental conditions. The rise in ambient temperature activates various internal mechanisms aimed at regulating core body temperature. Sweating is the most well-known of these responses, helping cool the body through the evaporation of moisture. However, this fluid loss places added strain on the cardiovascular system. To maintain adequate blood flow and supply oxygen to vital organs, the heart must work harder — often increasing heart rate and cardiac output by two to three times the normal levels.

This increased heart rate and strain on the cardiovascular system can be particularly dangerous for individuals with pre-existing heart conditions. As the heart works harder to meet the heightened demand for oxygen and maintain circulation, any inability to cope with this added stress can be harmful. For those with heart disease, such exertion can significantly increase health risks. Additionally, dehydration — common during heatwaves due to excessive sweating — can further exacerbate the situation. It causes the blood to thicken, potentially promoting clot formation and increasing the risk of heart attacks or strokes.

Heatwaves can further disrupt electrolyte balance, especially in individuals taking medications such as diuretics, which help eliminate excess fluid from the body. As sweating increases during extreme heat, the body not only loses water but also trace amounts of essential electrolytes like sodium and potassium, which are vital for maintaining homeostasis. An imbalance in these electrolytes can interfere with normal heart rhythm, potentially leading to arrhythmias. This can worsen existing heart conditions and elevate the risk of serious cardiovascular events.

Drink Water

Staying well-hydrated during a heatwave is essential for maintaining heart health, with a general recommendation to drink plenty of water.

However, individuals with heart failure or kidney conditions may need to adjust their fluid intake based on medical advice. In some cases, doctors may recommend relaxing fluid restrictions slightly in hot weather, especially for those taking diuretics, to prevent dehydration.

Including water-rich fruits such as watermelon, oranges, strawberries, and vegetables like cucumber in your diet can also help you stay hydrated. It is advised to avoid excess caffeine and alcohol as both can have diuretic effects, increasing fluid loss.

It’s also important to avoid outdoor exposure during the hottest part of the day — typically from late morning to early afternoon.

Dr. Joy Shome, Cardiologist and Head of TAVR/TAVI at BM Birla Heart Hospital, Kolkata.

health