Utility crews from Maine to Michigan and into Canada worked to restore power to more than half a million homes that were left in the dark by last weekend's ice storm, which has been linked to 27 deaths.
In the United States, the death toll from the storm reached at least 17, from traffic accidents and carbon monoxide poisoning. In Canada, 10 people were reported dead, including five who suffered apparent carbon monoxide poisoning as they attempted to heat their homes.
Police said two people in Ontario died after using a gas generator in a home northeast of Toronto. Police in Quebec said carbon monoxide poisoning was believed to be the cause of three deaths in a chalet on the province's North Shore. Earlier, five people were killed in eastern Canada in highway crashes blamed on severe weather.
The ice storm last weekend was one of the worst to hit during a Christmas week, and repair crews were working around the clock to restore service.
As temperatures plunged below minus 7 Celsius in Toronto, authorities reported a dramatic jump in calls for suspected carbon monoxide poisoning, responding to 110 calls in a 24-hour period. Officials say they typically see 20 such calls a day.
"I understand they want to keep warm, but you cannot do this. This is deadly," Toronto mayor Rob Ford said as the city issued an extreme cold weather alert. Fire officials warned residents not to use any appliance that burns inside a home - even candles.
"It's a real problem, a silent killer," said Joe Flynn, Vermont's director of emergency management and homeland security.
In Toronto, about 72,000 customers remained without power on Wednesday - down from 300,000. Elsewhere in Ontario, about 30,000 customers were still without power. In Quebec, some 28,000 customers remained without power. In New Brunswick, just under 30,000 customers were still in the dark.
Europe was also suffering from severe weather over the Christmas holiday.
In southern France, powerful winds and torrential rain grounded flights and cut off power to tens of thousands of homes.
About 50,000 homes across the country were without electricity on Christmas Day due to ruptured power lines and widespread flooding in the northwestern Brittany region, said France's ERDF power distributor.
Repair work by some 2,000 technicians throughout the day restored power to some 70,000 homes.
Hurricane-force winds have lashed France and Britain, causing five deaths in Britain and one in France. Heavy downpours led to cancellations of rail, flight and ferry services. Thousands of Britons woke up to flooding and power cuts on Christmas Day.
Associated Press, Reuters