A deadly heat wave that spread from Montana down to Texas—and back up north to Virginia—has killed 13 people, according to media reports. The heat is expected to last the next several days, the National Weather Service said, putting 18 states under heat warning, watch, or advisory. Temperatures in Illinois on Tuesday topped 110 degrees, while heat indexes in Minnesota were at 122. In Oklahoma, three-digit temperatures have lasted 28 days and roads have been reported to be cracking due to the heat. Officials said more than 1,000 heat records have been broken this month.