"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. Also known as the apparent temperature, the heat index is a number ...

Conditions are hot and humid in Michigan and getting hotter as the week goes on. Forecasters often refer to the heat index as a way to measure the "feels like" temperature. Here's a look at what 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 ...

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 ...