While Texas bakes under sweltering conditions, it's far from alone. Millions are under threat of extreme heat this week.

The map below identifies areas where the heat index is forecasted to reach NWS-defined levels from "Caution" (80 degrees Fahrenheit) to "Extreme Danger" (above 125 degrees).

Heat wave affects nearly 100 million: Heat advisories abound as almost 100 million Americans face 'ridiculous' temps National heat index map: See which states feel hottest The map below identifies ...

Multiple states are under extreme heat warnings, advisories or watches on July 23, according to the National Weather Service.