A Deadly Chill had much of the US and Canada in its wintry grip on 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.
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 US on Tuesday at a frigid -37 degrees Celsius. 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 degrees Celsius in Montana and was in the -40 to -50 degrees 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.
"To be fair, though, Mars is still way colder," the Smithsonian Institute wrote in a blog post. "The Curiosity rover is driving around in a crater at, roughly, the equivalent latitude of Venezuela."
But then again, Mars is 78 million miles further away from the Sun. For a more Earthly comparison, the Amundsen-Scott South Pole Station recorded a temperature of -23 degrees Celsius and a wind chill factor of -35 degrees Celsius on Tuesday.
The brutal chill came as people in the Great Lakes region were still digging out from two massive snow storms which dumped more than two feet of snow. More than 500 people spent Monday night stuck on a train that was stranded by snowdrifts on the line between Detroit and Chicago. Commuter rail - and even Chicago's famed elevated trains - were also knocked out of service by the snow and frigid temperatures froze switches and signals.
Nearly 2,500 flights were cancelled in the US on Tuesday and 3,400 were delayed. That brought the total of flights cancelled since the latest snowstorm hit on Thursday to more than 18,000.
Toronto's Pearson Airport temporarily halted ground operations early on Tuesday because of "equipment freezing" and out of concern for the safety of airport personnel, it said on its twitter account.
