Moorhead, Minn. area elementary school electronic sign shows cancellation of school because of frigid temperature Tuesday, Jan. 29, 2019. Daytime temperatures in the Fargo-Moorhead area were near -20F as Wednesday weather will be even colder. [Photo: AP]"

A brisk wind snaps the U.S. flags that line this automotive sales lot in north Jackson, Miss., Tuesday, Jan. 29, 2019. The National Weather Service has a winter storm warning in effect for parts of central Mississippi including Vicksburg, Jackson and Columbus. [Photo: AP]"

A Metra train moves northbound to downtown Chicago as the gas-fired switch heater on the rails keeps the ice and snow off the switches near Metra Western Avenue station in Chicago, Tuesday, Jan. 29, 2019. Forecasters warn that the freezing weather Tuesday will get worse and could be life-threatening. [Photo: AP]"

A worker arrives at the Metra Western Avenue Yard to inspect and work on the rail cars, Tuesday, Jan. 29, 2019, in Chicago. Forecasters warn that the frigid weather Tuesday will get worse and could be life-threatening. The extreme cold and record-breaking temperatures are crawling into a swath of states spanning from North Dakota to Missouri and into Ohio after a powerful snowstorm pounded the region earlier this week. [Photo: AP]"