This week's deep freeze grounded thousands of flights and halted dozens of trains in the region. Officials in some of the hardest-hit cities, such as Minneapolis, Detroit and Chicago, implored residents to stay indoors to prevent frostbite and to keep motorists off icy roads. With the biting cold moving out, temperatures will be all over the place in the next few days, a rapid change that will cause thermal whiplash for people living in affected areas. "Get ready for some serious ups and downs in the world of temperatures. That will be about 125 degrees in temperature change over seven days, it said.

Source: CNN February 01, 2019 09:13 UTC