Tens of millions of people across the Midwest and East endured dangerously hot temperatures again on Sunday as a sprawling June heat wave gripped much of the U.S.

A multiday heat wave is bringing high temperatures and health risks from the Midwest to the Northeast, prompting warnings and emergency measures.

Record-smashing daytime temperatures near 100 degrees are expected for millions from the Plains to the East Coast this week, while nighttime temperatures may stay above 80 in some metropolitan areas.