Heat index is the combination of humidity and air temperature. It's a metric that measures how hot it feels.

As Pittsburgh's temperatures climb toward triple digits, these are the key heat-related weather terms you should know.

Meteorologist Joe Puma warns that high humidity levels will significantly increase the heat index, making temperatures feel ...

The heat index is a measurement that considers both air temperature and humidity to determine how hot it actually feels to the human body.

ANGELES. WELL, WE ALL KNOW HOW HOT IT GETS HERE DURING THE SUMMER IN SOUTH FLORIDA, BUT IT ACTUALLY FEELS MUCH HOTTER WHEN YOU FACTOR IN THE HUMIDITY. FIRST WARNING METEOROLOGIST BROOKE SILVERING ...

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 ...

WASHINGTON — As the first heat wave of the season takes hold, people might be hearing a lot about "feels-like" temperatures. For example, WUSA9 meteorologists say at 4 p.m. Monday, the temperature ...

You've probably heard someone say during the summer, "It's not the heat, it's the humidity." And, they're kind of right. Both temperature and humidity factor into the "feels like" temperature — also ...

Add Yahoo as a preferred source to see more of our stories on Google. Heat kills more people in the U.S. than any other weather event. Thousands of people die from heat-related deaths each year.

Dangerous heat: The 'feels-like' heat index explained To stream 13News Now on your phone, you need the 13News Now app.