White Christmases are well-established in much of the United States. But that’s not really a reason to be happy, because it’s so bitterly cold that you can freeze to death within minutes. Millions of Americans cannot travel to see their families. And it can get worse.

An arctic cold front with temperatures as low as minus 40 degrees Celsius plunged large parts of the USA into chaos shortly before Christmas. Countless people could not start their trips planned for the festival; several states declared states of emergency. Meteorologists warned of a “bomb cyclone” with felt temperatures of up to minus 60 degrees Celsius and thus almost like on Mars.

The historic cold front moved east from the Midwest on Thursday. This Friday she reached the east coast of the USA. As early as Thursday evening, the middle of the country was in the vise of freezing temperatures.

Meteorologists called on people not to leave their homes if possible. If you go outside, you risk frostbite within minutes. For longer stays there is even a risk of death. President Joe Biden warned his countrymen: “This is not like a nice snowy day in childhood. This is really serious.”

The storm hit the country just before one of the annual travel highlights: According to the American Automobile Association, around one hundred million people are planning to travel by car over the Christmas period. But many roads were already closed on Thursday, especially in the north of the country. Thousands of flights have also been canceled or delayed.

In the state of South Dakota, authorities classified several expressways as “impassable”. Driving is “impossible due to the widespread deep snow and drifts,” said the state Department of Transportation.

Around 3,000 flights in or en route to the United States were canceled on Friday, according to flight-tracking website Flight Aware. Around 700 flights are likely to be delayed. Around 10,000 flights within the USA were already delayed on Thursday, and 2,600 were canceled. The international flight hubs in Chicago and Denver were particularly affected.

In the run-up to the storm, the US weather service had warned of “record-breaking cold and life-threatening gusts of wind” that would spread from the Rocky Mountains to the eastern half of the United States. A storm “of the kind that comes only once in a generation” was predicted for New York State.

New York Governor Kathy Hochul and her colleagues in several other affected states declared a state of emergency. Among other things, they warned of heavy rain or heavy snowfall, gusts of wind, flooding, black ice and the associated power failures.

The storm could quickly intensify into a so-called “bomb cyclone,” according to AccuWeather forecasts. It is caused by “bombogenesis”, a phenomenon in which cold and warm air masses meet with falling air pressure. In this case, the temperatures could feel as low as minus 60 degrees Celsius – according to the US space agency NASA, this almost corresponds to the temperature on Mars.

The weather service’s chief meteorologist in Glasgow, Montana, Rich Maliawco, warned of the dangers of such weather extremes. If people aren’t adequately dressed in such temperatures, they “can get frostbite in less than five minutes,” Maliawco said.

In many areas, the low temperatures were enough for the “Boiling Water Challenge”: Numerous videos on the Internet showed how people faced the “challenge” and threw boiling water into the air so that it immediately froze into a white cloud of ice.