'The US is bracing for temperatures to drop to their lowest in more than 20 years this week - with a windchill reading of -54C (-65F) forecast in western Minnesota.
A polar vortex coming down from the Arctic Circle will hit the Midwest in the middle of the week, according to the US National Weather Service.
The region will see life-threatening conditions in which frostbite and hypothermia can occur within minutes.
A frigid arctic air mass is expected to spread across much of the north central and northeastern U.S. this week. These are the coldest wind chill values expected over the next several days. Check forecasts from your local NWS office for details specific to your area. pic.twitter.com/zqsMZxPK7L
— NWS WPC (@NWSWPC) January 28, 2019
Wind chills will help some cities reach their lowest temperatures in decades.
Waterloo in Iowa is one of the places that could set an all-time low, and -36.6C (-34F) is forecast on Wednesday.
Chicago is already blanketed in snow but is set to hit -29C (-20F) on the same day. The last time it reached that temperature was 1994.'
Read more: Frostbite warning as polar vortex set to bring -54C to US Midwest