(CNN) -- Get ready for bone-chilling cold you probably haven't endured in years.
A deep freeze is spreading across much of the United States this weekend, making the nor'easter that just blanketed about 20 states with snow look like a mere curtain raiser.
Sunday temperatures are expected to hit 30 degrees below zero in North Dakota and other sections of the Plains and Midwest; the wind chill will make it feel like minus 50, the National Weather Service said.
By Wednesday, nearly half the nation -- 140 million people -- will shiver in temperatures of zero or lower.
The arctic blast threatens to sweep subzero lows as far south as Alabama and plunge much of the Deep South into the single digits.
Winter weather in the past week has claimed at least 13 lives, CNN has confirmed.
Eleven people died in road accidents -- including one man crushed as he was moving street salt with a forklift.
A man in Wisconsin died of hypothermia. And in Byron, New York, a 71-year-old woman with Alzheimer's disease wandered away from her home Thursday night and was found dead in the snow in a wooded area about 100 yards away.
in Chicago, a plane headed to Las Vegas slid off the taxiway at O'Hare International Airport on Saturday night. None of the customers on Spirit Flight 245 were injured, said Misty Pinson, director of corporate communications for Spirit.
The cold blast burst onto the stage in the Northern Plains States early Saturday, hurling North Dakota into below-zero territory.
Minnesota has already closed schools on Monday.
"I have made this decision to protect all our children from the dangerously cold temperatures," Gov. Mark Dayton said.
People in the town of town of Embarrass, Minnesota, say they may break their cold temperature record of 64 below, set in 1996.
"I've got a thermometer from the weather service that goes to 100 below," resident Richard Fowlei told CNN affiliate KQDS. "If it gets that cold I don't want to be here."
Chicago native Leo Londono, 30, said this is the harshest winter he's experienced in the city. From his apartment, he can see large chunks of ice floating on Lake Michigan.
"It's so cold you don't want to step outside," he said. "There's wind chill. And then this huge Arctic air blast is supposed to come through and I don't want to even leave my home."
The low temperatures and wind chill are a recipe for rapid frostbite or hypothermia.
A 66-year-old man died of hypothermia in Milwaukee on Friday, the medical examiner's office said.
The weather service's Twin Cities, Minnesota, office warns, "Exposed flesh can freeze in as little as five minutes with wind chills colder than 50 below."
This system will produce "the coldest air in two decades," the service said.
The danger of injury and death from the cold will spread with the cold front into the Midwest by Monday night.
Power outages were not as widespread despite blizzard-level winds in some places when the nor'easter passed through in the last few days.
Indiana Gov. Mike Pence encouraged residents to do more than check on friends and relatives.
"In preparation for the inclement weather, I encourage Hoosiers to assemble an emergency preparedness kit with plenty of non-perishable food and water, fill any necessary prescriptions, ensure they have a safe heating source, avoid unnecessary travel and be careful if they must be outside." he said.
Sunday night in Chicago will see a shivering 16 to 20 below zero and -- once you factor in the Windy City's stiff breeze -- a chill of 35 below to 45 below zero.
Lambeau Field in Green Bay, Wisconsin, is unfortunately not a domed stadium. Fans and players there will be outdoors and brave temperatures approaching minus 20 as the Packers battle the San Francisco 49ers for a chance to advance to the Super Bowl.
Some sportswriters speculated that it may go down in the record books as the coldest football game ever played.
The Packers organization and a stadium vending company will serve free hot chocolate and coffee to help fans withstand the deep freeze.
As Packers head coach Mike McCarthy said Friday: "This is not the norm."
That's is not the only game where fans will brave the freeze.
On Saturday in Philadelphia, the hometown Eagles hosted the New Orleans Saints in a playoff game. Temperatures were in the mid-20s at kickoff.
As the arctic cold conquers about half of the continental United States, temperatures are forecast to dip into the minus teens through the lower Midwest. Snow will cover swaths from the Plains to the Ohio and Mississippi River Valleys, all the way to New England.
Parts of the Midwest could see temperatures not recorded in 15 to 20 years -- for a painful couple of days.
Even areas as far south as Nashville could be frozen solid in zero-degree cold as the arctic air mass dives southward at the beginning of next week.
Thousands were stuck at airports nationwide Friday because of systemwide delays -- though at least they are not out in the frigid cold.
Lesley Ryland tried to get home to England after attending her son's wedding in Kentucky.
"I was supposed to fly from Kentucky/Louisville up to New York, but flights have been canceled at New York, so instead I've come here," Ryland told CBS Atlanta, a CNN affiliate. "Hopefully tonight, I'll get a transfer from here back over to London."
FlightAware.com, which tracks cancellations due to weather and mechanical problems, said about 3,200 flights were canceled Friday within, into or out of the United States.
Expect more of the same in the coming days. At 10 p.m. Saturday, 1,391 flights had been canceled. About 760 Sunday flights have already been called off.
Though the temperature in Las Vegas was 52 degrees -- above zero -- passengers there were also feeling the winter's sting Friday.
Long lines formed inside McCarran International Airport at the counters for Southwest Airlines, which had canceled many of its flights to and from Chicago. The airline carries 40% of Las Vegas' passengers, according to Chris Hayes, an airport spokesman.
CNN's Joe Sutton and Ralph Ellis contributed to this report.