Forecasters warned people to be wary of hypothermia and frostbite from the arctic blast sweeping across from the Midwest to the Northeast, where the temperature, without wind chill factored in, plummeted to -35C degrees in parts of New York state.
In Antarctica, temperatures are currently around -16C.
The prolonged, dangerous cold weather has sent advocates for the homeless scrambling to get people off the streets and to bring in extra beds for them. Warming centres were also set up in some locations.
Segundo Rivera and Sean Stuart told The Boston Herald they were not comfortable spending the night in a shelter.
“We’ve lived out here so long it’s like honestly, this is comfortable for us,” Mr Rivera said.
The Ohio Department of Ageing said older people were at increased risk from such severe cold, from medication side effects to falling risks, and encouraged people to check on family members, friends and neighbours.
Animal advocates also urged people to remember their pets. In Toledo, the humane society was looking into the death of a dog found “frozen solid” on a porch, cruelty investigator Megan Brown told The Blade.
“I don’t know how long she was out there,” Ms Brown said.
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Cold weather records were set from Arkansas to Maine, and the cold air will linger through the weekend, reaching as far south as Texas and the Florida Panhandle.
In New Hampshire, the cold set a record for the day of -37 atop the Northeast’s highest peak, Mount Washington.
In the Midwest, temperatures in Minneapolis are not expected to top zero this weekend.
A winter storm warning was in effect for much of Montana, calling for significant snowfall followed by dangerously cold temperatures as 2017 comes to an end.
“People like to think of themselves as being prepared for the weather and things like that,” Billings forecaster Dan Borsum said. “But this one will get your attention.”
Additional reporting by AP