Dangerously high temperatures to take over Midwest, excessive heat warning issued in Chicago

The heat will spread east and south through the week.

Thirty-eight million people are under heat alerts Monday as dangerously high temperatures are set to take over the Midwest.

An excessive heat warning has been issued in Chicago, where the heat index -- what the temperature feels like with humidity -- could reach a scorching 110 degrees on Monday and Tuesday.

The cities of Minneapolis; Madison, Wisconsin; and Omaha, Nebraska, are also under excessive heat warnings. The heat index may climb as high as 115 degrees in these cities on Monday.

In Detroit, public schools will be released three hours early on Monday and Tuesday due to the heat.

The heat will spread east and south through the week. Record highs are possible from Chicago to Louisville, Kentucky, on Tuesday and from Nashville, Tennessee, to Washington, D.C., on Wednesday.

This comes after record-high temperatures in Texas this weekend. Amarillo climbed to a record of 104 degrees on Sunday.

There are hundreds of deaths each year in the U.S. due to excessive heat, according to CDC WONDER, an online database, and scientists caution that the actual number of heat-related deaths is likely higher.

Click here for tips on how to stay safe in the heat.