Millions of US citizens are today facing a cold front so bad, weather officials are warning persons to stay indoors.
Some parts of the US will be colder than Antarctica.
A blast of arctic-chilled air from the polar vortex brought dangerous, record-setting cold to a wide swathe of the eastern United States on Tuesday, stretching from the Dakotas through Maine, with snow expected as far south as Alabama and Georgia.
The Midwest was the hardest-hit area, with a life-threatening wind chill bringing temperatures down as low as minus 46 degrees Celsius in the Chicago area and northern Illinois by Tuesday evening, the National Weather Service reported.
Wind chills in northern Illinois were expected to fall as low as -48C which the National Weather Service called "possibly life-threatening."
On Monday, snowplough drivers had trouble keeping up with the snow in Minnesota and Wisconsin, where some areas got as much as 38cm.
Chicago-area commuters woke up to heavy snowfall, with 13cm already on the ground.
There were around 1,600 flights cancelled in and out of Chicago over the past two days.
The deadly arctic deep freeze enveloped the Midwest US, forcing widespread closure of schools, offices and prompting the US Postal Service to take the rare step of suspending mail delivery to a wide swath of the region because of the cold.
As the area braces for the polar vortex, many schools have canceled.