Michigan's heat wave this week will feel even warmer because of high humidity. Here's how the heat index works.

The metric of how hot the air actually feels has roots in a 1979 journal paper called “The Assessment of Sultriness.” By Andy Newman In recent days, you may have seen or heard many mentions of a ...

The number on the thermometer only tells half the story. Here’s what to know about heat index—and why some scientists are rethinking how it is calculated.

Blistering heat and oppressive humidity are expected in the city of Chicago and parts of Illinois this week, with excessive heat warnings and heat advisories going into effect. Forecasters are warning ...

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

ROCHESTER, N.Y. (WROC) — Throughout the summer, much of the country has experienced at least a few days of extreme heat. In some cases, Americans were seeing large differences between real and ...

A persistent heat wave in Kentucky and southern Indiana is bringing a heat index that's soaring into the triple digits.