A heat wave in the South forced residents to contend with scorching temperatures and dangerously high humidity on Monday and Tuesday.

Temperatures were expected to climb above 100 degrees in some places, with heat indexes as high as 118 degrees, the National Weather Service said on Tuesday.

“For 2019, this is definitely the hottest we’ve seen so far,” said Thomas Winesett, a meteorologist with the National Weather Service in Jackson, Miss.

Excessive heat warnings on Tuesday affected more than 17 million people and applied to almost all of Mississippi and wide areas of Alabama, Arkansas, northwestern Florida, Louisiana and western Tennessee. There was another excessive heat warning in less humid regions in the Southwest, and a heat advisory was in effect across much of Texas and Georgia.