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.

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 ...

Each week, our meteorologists answer a question from readers.

What does the "heat index" mean and how does it apply to people? -- S.S., Tulsa. The World Almanac and Book of Facts, updated annually, always includes the heat index ...

Hundreds of people working or playing outside – even those who seem healthy – succumb to heat-related illnesses each year.

WEST MICHIGAN — We will truly be in the dog days of summer this week. A typical hot, summer July week is on tap. The attached image is from the National Weather Service. It’s a heat index chart that ...

The heat index is a measure of how hot it really feels on your body when relative humidity is factored in with the actual air temperature. Since heat index values were devised for shady, light wind ...