At least 28 people have died in the US as the country grapples with a brutal winter storm.
Blizzard conditions have left almost 300,000 homes and businesses without power, as temperatures plunge to well below freezing.
More than 3,000 flights were cancelled yesterday, with some airports closed.
On Friday more than 200 million people were under some form of weather warning.
Icy conditions on the roads prompted many authorities to warn against non-essential travel, and hundreds of people who did venture out found themselves stranded in their vehicles.
Among those who have died are three people in car crashes in Kentucky, and another three in Oklahoma, two of which happened as winds blew the drifting snow.
In Montana, the National Weather Service warned that the eastern slope of Glacier National Park and nearby foothills and plains could see up to 20.3cm of snow and winds of up to 90mph.
Montana saw a temperature of -45.6C (-50F) earlier in the storm, while yesterday’s low belonged to the remote town of Havre – also in Montana – which saw -39C (38F).
In Maine, more than 107,000 properties are without power and utility bosses have warned it could take days before supply is fully-restored, while some other states have asked customers to cut back on their usage to avoid rolling blackouts.
One company told its 65 million customers in 13 states that power plants were struggling to operate under the pressure of the weather and the extreme demand.
Another power company asked customers to drop their thermostats from 15.6C to 16.7C because a pipeline equipment failure had temporarily cut the gas coming from one of its suppliers by 30%.
Emergency shelters are being opened for those who are homeless or have no power at home, and there are also urgent efforts to get firewood to some Native American tribes who live in isolated areas.
In Portland, Oregon, severe weather shelters gave out tarpaulins and tents to people as the centres themselves closed due to a break in the bad weather.
More than 1,100 people had sought warmth at the city’s five emergency weather shelters, officials said.
In Buffalo, New York, deep snow, freezing temperatures and power cuts encouraged people to seek churches, police stations and anywhere else that might have heating.
Erie County executive Mark Poloncarz said ambulances needed more than three hours for a single trip to a hospital, with roads still hampered by snow, abandoned cars and downed power lines.
New York governor Kathy Hochul said the storm was “one of the worst in history”, and Timothy Carney of the Erie County Sheriff’s Office said: “It’s essentially a category 3 hurricane with a bunch of snow mixed in. It’s been like that for the past 24 hours.”