Getting too hot can make you sick. You can become ill from the heat if your body can’t compensate for it and properly cool you off. Heat exposure can even kill you: it caused 8,015 deaths in the United States from 1979 to 2003.

These are the main things affecting your body’s ability to cool itself during extremely hot weather:

•High humidity. When the humidity is high, sweat won’t evaporate as quickly, which keeps your body from releasing heat as fast as it may need to.
•Personal factors. Age, obesity, fever, dehydration, heart disease, mental illness, poor circulation, sunburn, and prescription drug and alcohol use can play a role in whether a person can cool off enough in very hot weather.
Here are some facts about which people are at greatest risk for heat-related illness and what protective actions to take to prevent illness or death:

•People who are at highest risk are the elderly, the very young, and people with mental illness and chronic diseases
•But even young and healthy people can get sick from the heat if they participate in strenuous physical activities during hot weather.
•Air-conditioning is the number one protective factor against heat-related illness and death. If a home is not air-conditioned, people can reduce their risk for heat-related illness by spending time in public facilities that are air-conditioned.
You can take these steps to prevent heat-related illnesses, injuries, and deaths during hot weather:

•Stay cool indoors.
•Drink plenty of fluids.
•Replace salt and minerals.
•Wear appropriate clothing and sunscreen.
•Schedule outdoor activities carefully.
•Pace yourself.
•Monitor people at high risk.
•Adjust to the environment.
•Do not leave children in cars.
•Use common sense.