A recent review article called attention to the connection between extreme heat and cardiovascular health. Research suggests individuals with cardiovascular disease are at four to seven times greater risk of dying from a cardiovascular event (heart attack, stroke, or heart failure) during extreme heat events. While the reasons behind this relationship are not fully understood, it is clear severe overheating (heat stroke) is not the only factor.
According to the authors, heat exposure increases heart rate, which in turn increases the amount of blood the heart muscle needs. People who have narrowed or clogged coronary arteries may not be able to meet this increased need, leading to increased risk of heart attack. Heat exposure may also cause an inflammatory response in the body. Inflammation can trigger blood clotting, which raises the risk for stroke and heart attack. Be particularly aware of your hydration state. (See Hydrating for Health on the following page for more information.)
On very hot days or during heat waves, spend time in air-conditioned spaces and use fans (always with some windows or doors open) in unairconditioned areas. Wetting your skin periodically, soaking your feet in tap water, wearing a water-soaked T-shirt, and sipping water or seltzer can also help keep your body cool.