AFP

CHICAGO-A deadly chill had much of the United States and Canada in its wintry grip Tuesday, as a record-breaking cold snap brought temperatures lower than on the surface of Mars.

It was so cold in Chicago that the polar bear at the Lincoln Park zoo - who admittedly had not built up the winter fat stores of her wild cousins - was brought inside to warm up.

And in Kentucky, an escaped inmate begged to be let back into prison so he could warm up after spending the night shivering in an abandoned house. All of Canada and all the US states bar tropical Hawaii recorded temperatures below freezing on Tuesday, even usually sunny and warm Florida and California. But the most dangerous cold - cold that can cause frostbite in a minute and death in a matter of hours - hit the Midwest, dragged down as the ‘polar vortex’ brought frigid air from the Arctic.

Schools, businesses and government offices were closed. Water mains and household pipes froze. Airplanes were grounded, trains were halted and roads and sidewalks became ice rinks. The town of Embarrass, Minnesota, recorded the lowest temperature in the United States Tuesday at a frigid -37 Celsius (-35 Fahrenheit). Then there was the wind chill: a calculation that represents how much colder it feels when the blinding gusts hit you in the face.

That dipped as low as -52 Celsius in Montana and was in the -40 to -50 Celsius range in parts of Illinois, Indiana, Iowa, Maryland, Michigan, Minnesota, Nebraska, North Dakota, Ohio, Pennsylvania, South Dakota, Virginia, West Virginia and Wisconsin. That’s cold enough to toss a cup of boiling water into the air and watch it turn into snow before it hits the ground. The Mars Rover has been sending back daily temperature readings from its tour of the Red Planet ranging from -25 to -31 degrees Celsius (-13 and -24 degrees Fahrenheit).