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 ...

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 ...

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 ...