The National Weather Service called the warm and above-average temperatures coming in behind the system "the first significant heat wave this season."

More than 37 million Americans are under heat advisories across the U.S., according to the National Weather Service. Here's the hardest hit areas.

The dangerous and record-shattering heat will shift east by the end of the weekend and the start of next week. Daily record highs are possible from Detroit to Raleigh, North Carol