MONTPELIER, Vt. - Train equipment froze, cars sputtered, schools canceled classes and cold-weather enthusiasts opted to stay inside Monday as a bitter blast of below-zero temperatures with promises of minus-50 wind chills gripped the Northeast and Midwest.
From Des Moines to International Falls to New England, temperatures went from single digits all the way down to more than 30º below zero.
The cold was linked to at least two deaths in the Northeast, including a Connecticut woman whose frozen body was found in a driveway.
Police said Denise O'Hara apparently fell in North Haven and froze to death Saturday night, when temperatures were close to zero. Her body was found Sunday morning after a neighbor called police.
About 90 miles northwest of Philadelphia, a man died after spending the night in his car in frigid temperatures in Lansford; his wife found him Saturday morning. Temperatures had dropped into the single digits overnight, Lansford police Detective Jack Soberick said, but it's unclear why Alan Kurtz, 49, had slept in his car.
With the mercury in a freefall, CBS News correspondent Marysol Castro reports many are warned not to venture outside, as experts say this brutal cold can turn dangerous quickly.
If people must go outside, doctors warn to dress warmly, as frostbite can begin to take effect in as little as five minutes.
"The cold affects the arteries of the fingers and the toes, so if you have any problems with the heart, diabetes, high blood pressure or other significant health issues, maybe going outside right now isn't the best thing for you," Dr. Suzanne Steinbaum told CBS News.
The gasp-inducing cold tested the mettle even of New Englanders, who pride themselves on winter hardiness.
"Snot-freezing cold," was how Kelly Walsh, 28, described it, walking home from an auto parts store in Vermont's capital after buying a new battery for her car, which wouldn't start Monday morning. It was minus 21 there at 7 a.m.
"I usually really like it," she said. "Today is a bit of nuisance."
Schools in western and northeastern Pennsylvania, across upstate New York and parts of Vermont and New Hampshire closed their doors or delayed openings to protect students from temperatures that dropped to minus 27 or even lower.
Amtrak suspended service between Albany and New York City, saying the extreme cold affected signals and switches. It hoped to resume service Tuesday.
"It takes your breath away if you're not ready for it," said Dan Giroux, shop tech at Northern Outfitters snowmobile rentals in Greenville, Maine, where the fleet was mostly idle because it was too cold for most folks.
Scientists at the National Oceanic and Atmospheric Administration tell The New York Times that one explanation for the frigid blast and erratic weather patterns this winter may be changes in circulation patterns which have typically kept cold air in higher latitudes.
They suggest that reduced pressure in the polar vortex has allowed a weakening of the jet stream (which acts as a divide between upper and lower latitudes), allowing colder air to escape the Arctic region and move further south, while warmer air is pushed up into the Arctic. Result: Melting ice caps and snow in Georgia.
Northern New England is used to cold winters; a remote site in northern Maine recorded a -50ºF reading on Jan. 16, 2009, that tied a 1933 record set in Vermont for the coldest temperature recorded in New England.
In Mr. Pocono, Pa., it was -6ºF around 6 a.m. Monday morning. Subzero temperatures were also recorded in western Pennsylvania, where the National Weather Service issued an advisory over wind chills as low as 20 degrees below zero.
In New York, the city doubled the number of outreach vans it sends out looking for homeless people in such cold, checking on street people every two hours.
"Our priority is to make sure they're safe and warm," said Seth Diamond, commissioner of the New York City's Department of Homeless Services.
In Providence, R.I., it dipped to minus 1 early Monday, the first below-zero reading there in six years, the National Weather Service said.
Even hat-shy teenagers were taking precautions.
"It's hard to get teenagers to bundle up, but even they're putting on their hats this morning," said Tim Scott, director of development at Fryeburg Academy, in Fryeburg, Maine, where it hit minus 28.
Skiers said "no thanks" at some resorts. At Maine's Sugarloaf, where a ski lift recently failed in windy weather and sent some riders to the hospital, the combination of cold and wind caused operators to shut down lifts to the summit. Four lower lifts were still running, however.
"We have a few people skiing - not many," said resort spokesman Ethan Austin. "There's a few hardy folks who want to get their turns in, no matter what."
Others took it in stride.
"It's a winter day in Maine," said Maude Gardner, of Allagash, in the northern part of the state, shrugging off a minus-24 reading Monday. After all, it was nothing compared to a minus-46 reading in January 2009.
The wind chill in some areas of New England was expected to make it feel as cold as minus 50. Wind chill advisories and warnings were also issued in upstate New York, including the Adirondack mountains, where Saranac Lake posted a reading of minus 36 early Monday.
In Philadelphia, a group of determined parents waited on a sidewalk overnight to enroll their children in kindergarten at a prestigious school run in partnership with the University of Pennsylvania. The Penn Alexander School eventually opened its doors, letting the parents in from the cold.
The cold air is expected to subside by Tuesday, just in time for the Northeast to be hit by another snowstorm, the sixth storm in just six weeks.