Temperatures are climbing, prompting your body to work overtime to cool down. This process places extra demands on the heart, especially for those with cardiovascular conditions.
Hermien Kalkman, a medical information advisor at the Heart Foundation, explains: "To release heat, you sweat more, as evaporating sweat cools the skin. Blood vessels in the skin also dilate, allowing the heart to pump more blood to the surface for cooling."
However, dilated vessels mean the heart pumps less blood per beat. Sweating reduces blood volume too. "The heart must beat faster and harder to deliver oxygen and nutrients throughout the body," Kalkman notes. "If your heart is already compromised, this can lead to shortness of breath, fatigue, or swollen ankles."
Thicker Blood Increases Risks
With wider vessels, blood pressure drops, and reduced fluid makes blood more concentrated. "The number of blood cells stays the same while volume decreases, making blood thicker and more prone to clotting," Kalkman warns. "This raises the risk of stroke or heart attack."
Care with Heart Medications
Staying cool is crucial, particularly for older adults and those on heart or blood pressure medications like diuretics. "These 'water pills' remove excess fluid," says Kalkman, "but in heat, they can lead to dehydration, disrupting water-salt balance and impairing sweating." Symptoms include headaches, cramps, nausea, dizziness, fainting, or unconsciousness.
Tips for Heart Patients
Everyone should drink plenty of water and avoid direct sun to ease the body's cooling efforts and reduce heart strain. For heart patients, check these tips for extreme heat and tailored advice from the Heart Foundation.
