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 ...

For example, when the air temperature is 100 degrees Fahrenheit, and the relative humidity is 55 percent, the heat index can shoot up to a sweltering 124 degrees Fahrenheit. And that’s in the shade.

You're not imagining it. Humidity really has gotten worse in the last 40 years. As temperatures rise across the U.S., here’s what you need to know about high humidity and how it can affect you.

High heat alone is a risk to humans, but heat and humidity together make an especially dangerous combination. Humidity has to do with the concentration of water vapor in the air, that cloying ...

The humidity also plays a role, making it feel hotter than the actual temperature, called the heat index. This is calculated by using the temperature versus the relative humidity. For example ...

Humidity impairs the body’s ability to release heat, more so in older people, said Dr. Rene Roberts, family medicine physician at Oak Street Health. “As we age, the body changes.

Heat stress: More than just temperature Beyond the heat index, meteorologists also track heat stress, or Wet Bulb Globe Temperature (WBGT). This index combines temperature, humidity, wind, sun angle, ...