A punishing heat wave will bring hot temperatures to eastern US and linger for several days, underscoring how climate change heats things up.

A Heat Advisory remains in effect with heat indices ranging from 100 to 110 degrees, and temperatures are expected to continue to rise until a cold front brings a cooldown on Wednesday night.

A phenomenon called "corn sweat" could exacerbate the impacts of the extreme heat blanketing a large portion of the U.S., according to experts.

Much of the U.S. is under extreme heat warnings or advisories while New York, Philadelphia and Washington could feel like 100 degrees or more.

An intense heat wave threatens millions of people across the Southeast with temperatures reaching 115 degrees through midweek.

Widespread showers and storms are likely to develop between 3 p.m. and 5 p.m., moving west to east. Tropical downpours with several inches of rain are possible under any thunderstorms, leading to localized flash flooding. There is also a lower-end severe weather threat with any storm, including damaging winds and large hail.