The subzero temperatures are already hitting but the worst is still yet to come on Wednesday where wind chill could bring temperatures as low as negative 50 in some parts.
"That's quite unsafe. You're talking about frostbite and hypothermia issues very quickly, like in a matter of minutes, maybe seconds", Hurley said. Wind chills in northern IL could fall to negative 55 degrees, which the National Weather Service called "possibly life-threatening".
The Midwest was the hardest-hit region, as temperatures plummeted below zero Fahrenheit (minus 17.8 degrees Celsius).
Some forecasts Monday were calling for temperatures to drop to minus-29 in Chicago, 2 degrees below its lowest temperature on record, set on January 20, 1985.
"That's 40 degrees below normal", Hurley said.
The biting cold already has caused at least one death in Minnesota and another in IL. And heavier snow is expected in the Upper Midwest and Great Lakes, meaning "dangerous to impossible travel conditions".
Snow will likely extend all the way down to MS and Alabama.
Meanwhile the northeast and parts of the south were contending with a snow storm, which had previously dumped up to a foot of snow (30 centimeters) in the Midwest over the weekend and still lingered in some areas Tuesday.
In Wisconsin, Governor Tony Evers has declared an emergency and requested help from the National Guard, according to the New York Times; In northern In, the University of Notre Dame said it would close its campus this evening through Thursday afternoon.
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The other, still pending in state court, is a class action suit seeking unspecified damages for season-ticket holders. The NFL has admitted in a document filed in court that an officiating mistake was made in the NFC championship game.
Air traffic in the region is affected, with more than 1,200 flights cancelled and as many delayed, the flight tracking site FlightAware.com reported early Tuesday.
If you're 25 years old or younger, "you've never felt this cold before", CNN meteorologist Tom Sater said.
"Frigid temperatures and bitterly cold wind chills" will likely result in widespread record lows across much of the country, culminating in a combination of winter storm and wind chill warnings, watches, and advisories across the central part of the country.
The cold also prompted officials to close some schools in eastern Iowa, while Chicago Public Schools officials said that Wednesday's classes have been canceled due to the anticipated cold snap. They keep dropping Wednesday and even Thursday.
Amy Patterson, a vice president at the Atlanta Super Bowl Host Committee, said there was enough time for the freeze to pass to allow fans to fly to Atlanta in time for the game, with the National Weather Service forecasting a high of a balmy 58F (14C) on Sunday. "That is our number one goal", Emanuel said.
Chicago Mayor Rahm Emanuel urged residents to check on their neighbors and take safety precautions.
Jennifer Francis, senior scientist and Arctic expert at the Woods Hole Research Center in Falmouth, Mass, said that while the latest move in the polar vortex "may unleash claims that global warming is a hoax", the mass of frigid air over North America is far outweighed by areas elsewhere that are warmer than usual.
Chenard said a polar vortex refers to the upper level jet stream that typically circulates around both the North and South Poles, keeping the coldest air there.