A heat dome​ is trapping over 90 million Americans in extreme temperatures this week with the National Weather Service​ issuing heat alerts from Nebraska to Florida.

It’s the hottest time of the year in the United States and another heat dome is about to make millions of people feel every bit of it.

These expansive areas of sinking air can push temperatures up to 30 degrees above average during the summer while increasing the threat of heat illnesses.

How hot will it get as the humidity builds and a heat dome spreads toward the Northeast? What is a heat dome? Here's what to know and what it means.

The process is officially known as evapotranspiration, which is how plants, including corn, release water vapor into the ...

Heat and humidity will once again smother the eastern half of the country this week, pushing the heat index to dangerous levels for tens of millions of people. In the Midwest, the humidity will be ...

Even without reaching heat wave levels, sustained high temperatures may contribute to a litany of health issues.

Your blood pressure can decrease when it's hot outside. Heat and humidity can increase the risk of cardiovascular events.

Extreme heat events increasingly pose significant global health risks, especially in vulnerable and under-resourced regions.

Almost 85 million Americans from South Dakota to Texas and North Carolina to Florida are already under extreme heat warnings, watches or advisories.

After a large-scale power outage that left thousands in Ottawa without cooling on July 13, Environment and Climate Change ...