Hunker down at the heater. The numbing blast of cold air slapping your cheeks Sunday morning is only the warm-up for a dangerous onslaught of frigid weather.

"I'm expecting to be trapped," Laura Baier of Minneapolis said Saturday as she stocked a cart full of bread, fruit and vegetables at Rainbow Foods, which is shutting down all Minnesota stores Monday evening so employees and truck drivers aren't out in the historic cold. "I'm expecting my car to not start for one, two, three days."

At grocery stores, gas stations and garages Saturday, many Minnesotans braced for the coldest temperatures to hit the state in nearly two decades. Temperatures will remain at 10 to 20 degrees below zero statewide Sunday and are expected to hit between -25 and -35 in the metro area Sunday night. Monday's high temperature could be -20.

Thermometers in northern Minnesota will dip even further. Windchills will turn the record-threatening readings life-threatening, assaulting exposed skin with the equivalent of minus-65 degrees.

On Sunday morning, the National Weather Service in the Twin Cities tweeted: "This is the first time we have used the 'particularly dangerous situation' (PDS) wording with a Wind Chill Warning."

At a windchills of 35 degrees below zero, flesh will freeze within 10 minutes. At 50 below, it takes only five minutes.

That prompted Minneapolis parks to shut down all programs until Tuesday and businesses like 3M in St. Paul to close Monday. Gov. Mark Dayton also took the rare step of canceling school statewide Monday even though some northern Minnesota schools scoffed at the decision after tolerating similar temperatures last week.

The resounding advice from officials: stay indoors.

Hardy or foolhardy?

But some hardy Minnesotans took the looming Arctic blast in stride, making jokes about how Antarctica and even Mars will be warmer than some spots in Minnesota. Others soaked up sunshine on ice rinks or ski trails Saturday before the temperatures plunged, closing park buildings and programs.

"I love this weather. Where else can you get weather like this?" said Edric Lysne after teaching a cross-country ski lesson at Wirth Park.

He's especially gutsy, planning to brave the subzero temps and windchills by hiking along the Mississippi River on Monday and camping under stars in his back yard Sunday night, snuggled in a sleeping bag made for 50 below temps.

"That whole idea of resiliency and testing yourself … I get excited," he said, adding that he has the proper cold-weather gear to make it safe.

Camping out inside

Others will heed the warnings and stay out of the cold.

"If it's as bad as it is, no way," Kerry Roth of Minneapolis told her kids about going outside Monday. Instead, she said, she'll take the four kids to a trampoline park or pass time at home.

The family skated Friday and Saturday on Lake of the Isles to soak up the warmer weather before the park program shuts down until Tuesday. Less than a week into 2014, Roth already is weary of the bone-chilling temperatures that also closed out 2013. "It feels like we only had one week of summer," Roth said.

But her husband, Brad Sorock was more encouraged. "After 20 below, we'll be in T-shirts when it's 10 above," he said.

It may be a while before the short sleeves appear.

Thursday's high could tickle 20 degrees, but until then it will remain downright cold.

The source of all the frigidity is a "big chunk of air mass that has broken off," from an area near the North Pole and the Northwest Territories of Canada, said Jim Taggart of the National Weather Service. It has moved into Minnesota virtually unchanged.

"In past years when we may not have had as much snow, the Canadian air gets a little warmer as it reaches Minnesota and the cold is not as pronounced," Taggart said. But this year there's plenty of snow everywhere.

Extra measures

The arctic blast will bring a bump in business for some companies. AAA in Minnesota and Iowa is bracing for up to 4,000 service calls Monday, an increase of 50 percent or more than usual, spokeswoman Gail Weinholzer said.

Both CenterPoint Energy and Xcel Energy are also ramping up the number of staff on hand in anticipation of extra service calls. Xcel also asked nearly 600 Minnesota and North Dakota businesses to lower their natural gas use starting on Sunday to make more fuel available to heat homes across the region.

Through midweek, extra measures will be in place for homeless children and adults. YouthLink, a resource center for homeless and at-risk teens and young adults, opened at 8 p.m. Saturday and will be open around the clock until 8 a.m. Wednesday. Hennepin County said shelters for single adults, which normally close during the day, will also remain open and the Harbor Light Center in Minneapolis will accept anyone needing shelter.

Staff writer Tom Meersman contributed to this report.

Kelly Smith • 612-673-4141

Twitter: @kellystrib