Half the Nation Faces Fourth of July Heat Wave as 160 Million Under Alerts

A dangerous Fourth of July heat wave is bearing down on the U.S., with more than 160 million people under heat alerts as humid conditions push heat indices into the 90s and 100s in many cities (Chicago could reach a 101-degree heat index). NBC’s seven-visual data package maps where, when and how bad the heat will be, highlighting risks to outdoor plans, increased energy demand, and vulnerable populations who should stay hydrated, seek shade, and limit sun exposure during the holiday weekend.