Cities are all but shutting down across the US Midwest as the region shivers in a deadly cold snap known as a polar vortex.
At least seven people have been killed in several states as a result of the arctic weather.
Temperatures fell to -30C (-22F) in Chicago – colder than parts of Antarctica – and -37C in North Dakota.
Freezing weather will chill 250 million Americans, and 90 million will experience -17C (0F) or below.
Snow is expected to fall throughout Wednesday, from the Great Lakes region into New England. As much as 24in (60cm) is forecast in the state of Wisconsin, and 6in in Illinois.
States of emergency have been declared in Midwestern Wisconsin, Michigan and Illinois, and even in the normally warmer Deep South states of Alabama and Mississippi.
“This could possibly be history-making,” said Ricky Castro, a National Weather Service (NWS) meteorologist in Illinois.
The NWS is warning frostbite is possible within just 10 minutes of being outside in such extreme temperatures.
Grand Forks, North Dakota, has seen the lowest wind chill so far at -54C on Wednesday morning.
Twenty million people in the continental US are expected to experience temperatures of -28C or lower by the week’s end.
Photo credit: Getty Images/BBC