Extreme heat causes more deaths than any other weather-related hazard. According to the CDC, each year more than 65,000 people seek medical treatment for extreme heat exposure.

To combat these numbers, the CDC has developed an updated app for use on mobile phones and other portable computing devices. The app helps calculate the heat index–a measure of how hot it feels–based on the combination of temperature and humidity.

More information on heat-related illnesses and a link to download the app