Trees frozen in ice cripple a section of power lines on Maplehurst Drive in Belgrade, Maine, Tuesday, Dec. 24, 2013. From Michigan to Maine, hundreds of thousands remain without power days after a massive ice storm _ which one utility called the largest Christmas-week storm in its history -- blacked out homes and businesses in the Great Lakes and Northeast. (AP Photo/The Central Maine Morning Sentinel, Michael G. Seamans)

Repair crews worked around the clock to restore power to nearly half a million customers who faced a cold and dark Christmas in parts of the central and northeastern United States 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 U.S. 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 poisoning. Police said two people in Ontario died after using a gas generator to heat their blacked-out 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 conditions.

In the U.S., 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 collision that happened Monday to the storm.

As temperatures plunged into the low single digits (below minus 15 Celsius) in Toronto —where nearly 80,000 customers remained without late Tuesday—authorities reported a dramatic jump in calls for suspected , responding to 110 calls in a 24-hour period. Officials said they typically see 20 such calls a day.

"We're looking at approximately six times as many calls," Toronto 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."

Andrew Powers, an arborist with Asplundh Tree Experts, clears iced branches from power lines along Mayflower Heights Drive in Waterville, Maine, on Monday, Dec. 23, 2013. Central Maine Power said nearly 57,000 were without power Monday afternoon, up from 29,000 it had been reporting earlier. Hardest hit was Kennebec County with about 20,000 and Waldo County at nearly 15,000 customers without power. (AP Photo/Morning Sentinel, Michael G. Seamans)

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

Trees and power lines grow heavy with ice as freezing rain continues into Monday morning, Dec. 23, 2013, in Cambridge, Vt. From Michigan to Maine, hundreds of thousands remain without power days after a massive ice storm -- which one utility called the largest Christmas-week storm in its history _ blacked out homes and businesses in the Great Lakes and Northeast. (AP Photo/Burlington Free Press, Emily McManamy)

Elsewhere in Ontario, more than 44,000 customers were still without power early 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.

Carla Coulter, 46, of Clio, holds her 1-year-old grandson Connor Hergert closely as she gives him a kiss on the forehead while listening to the FirstMerit Bank Mixed Chorus sing "Silent Night" along with about 100 spectators during the 76th Annual Holiday Sing on Tuesday, Dec. 24, 2013 at FirstMerit Bank in downtown Flint, Mich. "We don't have power. We're warming up, and I just feel so very blessed to have my family," Coulter said. "I don't need anything else." (AP Photo/The Flint Journal, Jake May)

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

Some U.S. states kept emergency shelters open for people without power.

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 1,000 workers to restore power for all customers by Thursday night, while other utilities in Maine warned customers they could be without electricity until Friday.

Jake Baldino, left, and Mick Benbow of K & T Electric of DeWitt replace an electrical box and pole to a home in DeWitt Township, Mich., Monday, Dec. 23, 2013. From Michigan to Maine, hundreds of thousands remain without power days after a massive ice storm -- which one utility called the largest Christmas-week storm in its history -- blacked out homes and businesses in the Great Lakes and Northeast. (AP Photo/Lansing State Journal, Greg DeRuiter)

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

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

Lights on the Christmas tree were dark, of course, but there was no power to the freezer, either. "Even though the house is freezing cold, the freezer items were starting to thaw out," Potbury said.

Utility crews respond to a downed power line at the intersection of Dorset Street and Kennedy Drive in South Burlington, Vt., on Monday, Dec. 23, 2013. From Michigan to Maine, hundreds of thousands remain without power days after a massive ice storm _ which one utility called the largest Christmas-week storm in its history -- blacked out homes and businesses in the Great Lakes and Northeast. (AP Photo/Burlington Free Press, Glenn Russell)

That wasn't the greatest concern, however, for his kids, 8-year-old Jacob and 5-year-old Jackson. Potbury said he told them Tuesday, "Santa runs on reindeer power, not electricity, so he should be OK."