The temperature on any given summer day may be in the 80s or 90s. So why does it feel so much hotter and oppressive at times? That's the heat index doing its thing. Here's how it works: What is the ...

Add Yahoo as a preferred source to see more of our stories on Google. "It's not the heat, it's the humidity." Actually, it's both, and that's where the National Weather Service's heat index comes in.

Rochester is entering its first heat wave of the summer, with an air temperature above 90 degrees expected for the next four days. The heat index will be even higher, expected to exceed 95 degrees ...

Add Yahoo as a preferred source to see more of our stories on Google. The temperature on any given summer day may be in the 80s or 90s. So why does it feel so much hotter and oppressive at times? The ...

If you thought the worst of the summer's sweltering temperatures were behind us, think again. Some schools closed early as the late-August heat wave gripping Ohio brought temperatures not seen in ...