How does hot weather affect the heart?
Extremely hot weather causes dehydration, heat exhaustion and heat stroke. These risks increase when the humidity is above 70 percent and the temperature is above 70 degrees F. Heat and humidity interfere with the body’s natural cooling process. Exercising outside in hot and humid conditions can be hard on your heart. This is true even for athletes who haven’t yet adapted to the heat. The problem is made worse because the heart is trying to deliver blood and oxygen to your working muscles while your body is trying to cool off by sweating. If you sweat too much, you lose fluid. This decreases your total blood volume. That means your heart has to pump even harder to get the smaller volume of blood to your working muscles, skin and the other body parts. When you lose too much fluid, your body temperature rises and your nervous system doesn’t work properly. Extreme fluid loss can lead to brain and heart damage. A good way to monitor your body fluid level is to weigh every morning after usi
