From a story on axios.com by Andrew Freedman “Expanding heat wave leaves more than 112 Million under alerts”:

An expanding, intensifying heat wave prompted the National Weather Service to issue heat alerts for more than 112 million people on Thursday morning, with no letup in sight for some areas.

Why it matters: The heat will topple longstanding records, especially in the Southwest, and the duration of this event that’s set to continue well into next week increases public health dangers.

The big picture: This heat wave is already notable for its scope, intensity and endurance.