There's no relief yet from the heat wave that was set over most of the U.S. and made its way to Delaware. The National Weather Service has issued an extreme heat warning for nearly all of Delaware through Wednesday,

With a heat wave causing excessive heat warnings in Delaware, you'll hear a lot about the heat index this week. What to know and how to stay cool.

It's oppressive outside today in Pennsylvania, as heat indices may near 110 degrees. When is relief on the way? Here's the forecast, heat maps, more.