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 ...

Temperatures this week are some of the hottest we have seen the entire year now as we get to the end of July. This is a perfect opportunity to explain what the Heat Index is and how it is all ...

The wind affects the feels-like temperatures during the winter and the summer, but strong winds are more noticeable in the ...

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 ...

Heat is the number one weather-related killer. We break down what you need to know to stay safe.