Not unlike the recent heat wave that just engulfed much of Europe, the U.S. Southeast is bracing for triple-digit figures on the Heat Index.
Philadelphia could see highs in the 90s over the next three to four days, as parts of the Midwest have already seen a heat advisory issued for Tuesday. Because of higher humidity, parts of the Southeast are likely to feel like 100 degrees-plus.

A heat advisory was issued on Tuesday.
ABC News

Temperatures may be even hotter in many spots on Thursday.
ABC News
The hottest weather on the Fourth of July holiday will stretch from the Gult Coast to the mid-Atlantic, with temperatures in the 90s and more high humidity expected in cities including Atlanta and Washington.