The heat index is a measure of how hot it really feels on your body when relative humidity is factored in with the actual air temperature. Since heat index values were devised for shady, light wind ...

Extreme levels of heat and humidity are forecast to spread across the country over the next two weeks, blanketing the Southwest, Midwest, and East Coast with high temperatures beginning this June 19 ...

The heat index, or apparent temperature, combines air temperature and relative humidity to indicate how hot it feels. High humidity slows sweating, the body's natural cooling system, making ...