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 ...

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 ...

While they all signal hot and potentially dangerous conditions, each alert type has a specific meaning, and knowing the difference could help you avoid heat-related illness. A heat advisory is issued ...