Repair crews worked around the clock to restore power to nearly half a million people who faced a cold and dark Christmas in parts of the central and north-eastern US and into eastern Canada after a weekend ice storm. At least 24 deaths have been linked to the storm.

It appears the bad weather isn't ready to take a break. The US National Weather Service said more snow is forecast to roll into the Great Lakes and midwest by Wednesday morning.

In Canada, five people were reported dead from apparent carbon monoxide poisoning. Police said two people in Ontario had died after using a gas generator to heat their blacked-out home north-east of Toronto.

Police in Quebec said carbon monoxide poisoning was believed to be the cause of three deaths in a chalet. Earlier, five people were killed in eastern Canada in highway crashes blamed on severe weather.

In the US, the nationwide death toll from the storm reached at least 14 on Tuesday, when a 50-year-old man in Knox, Maine, was overcome by carbon monoxide fumes from a generator. It was the second reported death attributed to fumes from a generator during the storm. Police in Michigan also attributed two deaths in a traffic crash on Monday to the storm.

As temperatures plunged below -15C in Toronto, where nearly 80,000 customers remained without power late on Tuesday, authorities reported a dramatic jump in calls for suspected carbon monoxide poisoning, responding to 110 calls in a 24-hour period. Officials said they typically had 20 such calls a day.

"We're looking at approximately six times as many calls," Toronto’s mayor, Rob Ford, said as the city issued an extreme cold weather alert. "I understand they want to keep warm but you cannot do this. This is deadly."

Fire officials warned residents not to use any appliance that burns inside a home, and even cautioned against using several candles.

In Toronto, where 300,000 customers lost power at the height of the storm, crews from Ottawa, Windsor, Manitoba and Michigan were helping local teams with their efforts.

Elsewhere in Ontario, more than 44,000 customers were still without power early on Wednesday. In Quebec, some 28,000 customers remained without power. In New Brunswick, just over 29,000 customers were still in the dark, and about 300 were without power in Nova Scotia.

Canadian utility officials warned that some customers could be without power until Saturday.

Some US states kept emergency shelters open for people without electricity.

The number of customers in Maine without power spiked to more than 100,000 on Tuesday. Central Maine Power said its goal was to use more than 1000 workers to restore power for all customers by Thursday night, while other utilities in Maine warned customers they could be without electricity until Friday.

That was the case in Michigan, where Consumers Energy said it hadn't had this many outages during any Christmas week since its founding 126 years ago. Close to 17% of its 1.8 million electric customers lost power during the storm that hit late Saturday; roughly 152,000 remained without it on Tuesday.

At their home outside Flint, Michigan, John Potbury and his family of four lost electricity at 6 am on Sunday and since then they have been living in a single bedroom warmed by generator-powered space heaters.

"Even though the house is freezing cold, the freezer items were starting to thaw out," Potbury said.

That wasn't the greatest concern, however, for his chirdren – Jacob, eight, and Jackson, five. Potbury told them: "Santa runs on reindeer power, not electricity, so he should be OK."