The coldest, most dangerous blast of polar air in decades gripped the US Midwest and pushed toward the east and south, along with eastern Canada, closing schools and day care centres, grounding flights and forcing people to pull their hoods and scarves tight to protect exposed skin from nearly instant frostbite.
Many across the nation’s midsection went into virtual hibernation, while others dared to venture out in temperatures that plunged well below minus 18 degrees Celsius.
“I’m going to try to make it two blocks without turning into crying man,” said Brooks Grace, who was bundling up to do some banking and shopping in downtown Minneapolis, where temperatures reached minus 31 degrees, with wind chills of minus 45 degrees. “It’s not cold – it’s painful.”
The mercury also dropped into negative territory in Milwaukee, St Louis and Chicago, which set a record for the date at minus 27 degrees Celsius. Wind chills across the region were below 40 and colder. Records also fell in Oklahoma, Texas and Indiana.
Forecasters said some 187 million people in all could feel the effects of the “polar vortex” by the time it spread across the country on Monday night and Tuesday.
Record lows were possible in the East and South, with highs from minus 17 to minus 13 degrees expected on Tuesday in Georgia and Alabama.
For a big swathe of the Midwest, the bone-chilling cold moved in behind another winter wallop: more than 30cm of snow and high winds that made travelling treacherous.
Watch: Deep freeze hits northeastern United States
Several deaths were blamed on the snow, ice and cold since Saturday, including the death of a one-year-old boy who was in a car that went out of control and collided with a snow plough on Monday in Missouri.
It took authorities using 10-tonne military vehicles known as “wreckers” until early Monday to clear all the chain-reaction accidents in southern Illinois. The crash stranded about 375 vehicles, but there were no fatalities or injuries, largely because motorists either stayed with their cars or were rescued and taken to nearby warming centres.
Others got stuck in the snowdrifts, including the Southern Illinois men’s basketball team, which had to spend the night sleeping in a church.
In the eastern United States, temperatures in the low teens Celsius on Monday helped melt piles of snow from a storm last week, raising the risk that roads would freeze over as the cold air moved in Monday night, said Bob Oravec from the Weather Prediction Centre in Maryland.
More than 3,700 flights were cancelled by late Monday afternoon.
Airline officials said de-icing fluid was freezing, fuel was pumping sluggishly and ramp workers were having difficulty loading and unloading luggage.
In Indiana, utility crews worked to restore power to more than 40,000 customers affected by the weekend storm and cautioned that some people could be in the cold and dark for days.
Ronald Smith Snr took shelter at an Indianapolis Red Cross after waking up the previous night with the power out and his cat, Sweet Pea, agitated in the darkness.
“The screen door blew open and woke me up, and it was cold and dark. I got dressed and I was scared, thinking, ‘What am I going to do?’ My cat knew something was wrong. He was jumping all over the place,” Smith said. “This is brutal cold. The cold is what makes this so dangerous.”
Officials in Chicago and other cities checked on the homeless and shut-ins for fear they might freeze to death on the street or in their homes.
In Canada, much of Saskatchewan and Manitoba were in a deep freeze on Monday with temperatures near or below minus 30 degrees and wind chills colder than minus 40.
In Newfoundland, about 5,000 customers remained without power because of rolling blackouts in recent days, but Premier Kathy Dunderdale said it was not a crisis and government services were still operating.