At least seven deaths are blamed on the weather.
Cold air surging from the Arctic stretched from the northern Plains through New England, and temperatures were below zero as far south as the mountains of West Virginia, but slightly milder weather was on the way.
Elderly residents of an apartment complex in Chicago say they managed to survive three subzero days without heat, wrapped only in blankets. And as if the cold weren't enough, a new storm front dumped as much as six inches of snow across large stretches of the Midwest, causing dreadful drives, CBS News correspondent Cynthia Bowers reports.
Dozens of school districts in western and central New York closed for a second day, including Buffalo and the 34,000-student Rochester district, because of the cold and locally heavy snow.
Rochester had a late-morning temperature of 13 degrees, but wind whipping through the city at 22 mph made it feel like 5 below zero, the National Weather Service said.
The wind also picked up moisture from the Great Lakes and turned it into 3 to 4 feet of snow on New York state's rural Tug Hill region, downwind from Lake Ontario.
The city of Fulton got seven inches of snow in a two-hour period during the night — and at one point crews stopped plowing because the snow was falling too fast.
"It's horrible driving," said Chris Sachel, who owns Mimi's Drive-In Restaurant, just north of Fulton. "Pretty much the only people we've seen this morning are the plow drivers. They're about the only ones who can get around."
Snow also made roads slippery across part of the Midwest. In the Minneapolis-St. Paul area, a pileup on Interstate 35 involved four tractor-trailer rigs and several cars, the State Patrol said.
With a Tuesday morning low of 6 degrees below zero, Milwaukee kept its schools closed for a second day, idling some 90,000 children. On Monday, the temperature fell to 12 below with a wind chill of 31 below.
Hundreds of Michigan schools also remained closed.
Temperatures started easing Tuesday in places where the cold was the worst. After Monday's low of 38 below zero, the northern Minnesota town of Hallock reported a Tuesday morning reading of just 9 below, the National Weather Service said.
"It's bitterly cold ... (but) the coldest of it is over," said Mark Ratzer, a senior forecaster with the National Weather Service in Romeoville, Ill., near Chicago. The Tuesday morning reading at O'Hare International Airport was zero, compared to minus 10 some 24 hours earlier.
Pockets of intense cold lingered, however, including 29 below at International Falls, Minn., snug up against the Canadian border, and 20 below at Ironwood, Mich.
And the longer temperatures stay low and the ground stays white, the less green will be in people's wallets, Bowers reports. Oil and natural gas prices shot up as soon as the mercury went down.
Homeless shelters tried to keep the most vulnerable people safe. Repairers of the Breach, a daytime facility for the homeless in Milwaukee, has expanded to 24-hour operation since Friday as the temperatures plunged. The shelter doesn't have beds but provides blankets, pillows and meals for people who had nowhere else to go because other shelters were full, said MacCanon Brown, executive director. Fifty-one people stayed there Sunday night.
"Once this cold spell hit, we were just so aware that there are so many people outside or in unheated places," Brown said. "We know that there would be a lot of deaths and terrible frostbite and hypothermia if we weren't open."
Xcel Energy asked customers in North Dakota, Minnesota, Michigan, South Dakota and Wisconsin to conserve electricity over the next few days to reduce strain on the power grid. The company said it has enough electricity supplies "but it is possible that electricity reserves could tighten as people begin to use more during evening hours."
The cold was too much for plumbing across Chicago, and crews were sent to more than 1,000 reports of frozen pipes, city officials said. It also strained vehicle batteries, prompting numerous calls for help from motorists. "The total for yesterday, and this is a record for recent years, is 9,239 calls for assistance," AAA Michigan spokeswoman Nancy Cain said Tuesday.
The cold contributed to two deaths in Kentucky, two in Michigan, and one each in Maryland, Ohio and Illinois, authorities reported.
In Maryland, 81-year-old Annie Mae Anderson of Silver Spring, who suffered from dementia and was found Monday in a wooded area. She apparently had wandered away from her house without a coat and appeared to have died from exposure to the cold, said Montgomery County police Lt. Eric Burnett.
The cold contributed to two weekend deaths in Kentucky: an elderly man who wandered away from his home Sunday and a motorist whose car slid on ice and overturned in a river, authorities said. An 8-year-old girl and her mother were killed in a wreck on an icy road in Michigan, state police said. The body of a 47-year-old man was found outdoors in Ravenna, Ohio, and police said drunkenness contributed to his death. The medical examiner's office said 25-year-old Tamika Mitchell died in Chicago from both the cold and drug use combined.
Authorities were unsure whether to attribute other deaths to the extreme cold, such as thein Bardstown, Ky.