John Bacon and Doyle Rice

USA TODAY

Records fell, power grids were challenged and travel remained a snarled mess Tuesday as a brutal mass of Arctic air continued its crawl across a large swath of the nation.

More than a 20 deaths have been linked to the bitter chill and snowstorms that began rolling across the Midwest heading east late last week. Dozens of temperature records fell Tuesday. But there were also signs that the better days were on the way.

"The big story today is it's still bitter cold across the Great Lakes and the East," AccuWeather senior meteorologist Tom Kines said. "But we are already seeing moderate air pushing into North Dakota. We just gotta get through today."

That was no small order. The subzero temperatures forced school closings across dozens of states, kept people home from work, jammed up travel and made stepping outside a risky proposition.

Scores of record-low temperatures were reached Tuesday morning in the South, East and Midwest, the Weather Channel reported. Among them: New York City (4 degrees), Atlanta (6 degrees), Philadelphia (4 degrees), Baltimore (3 degrees), Cleveland (minus-11 degrees), Detroit ( minus-14 degrees) and Charlotte (6 degrees).

New Yorkers who saw temperatures above 50 degrees Monday were dealing with 4 degrees Tuesday — with a wind chill deep into negative numbers. Some roads were closed in the western and central parts of the state.

"I am urging New Yorkers in the area to stay home today," said Gov. Andrew Cuomo. "Anyone who must travel should exercise extreme caution."

Energy demand in a 13-state region from Michigan to Virginia shattered a seven-year record Monday night, drawing a rare winter call for consumers to conserve. PJM, the regional transmission organization, recommended setting thermostats lower, postponing use of major appliances, and turning off idle electrical devices and appliances.

Air travel, all but impossible Monday, was only a little better Tuesday. More than 3,600 scheduled commercial flights were canceled and more than 8,000 others delayed, Flightstats.com reported. On Monday, more than 5,000 flights were canceled and more than 10,000 more were seriously delayed.

More than 500 Amtrak passengers spent the night stranded on three trains headed for Chicago because blowing and drifting snow blocked the tracks in north-central Illinois. Spokesman Marc Magliari said all the passengers, traveling from Los Angeles, San Francisco and Quincy, Ill., had been evacuated from the trains and would reach their destinations either by train or bus later Tuesday.

In Cincinnati, security guard Cassandra Lenzley was patrolling outside three downtown high-rises early Tuesday. The temperature dipped to 7 below, with a wind chill of minus 26.

"It's stinging cold," Lenzley said. "Your skin burns if you are out too long. You can feel it through your clothes, and I have on three layers."

Tuesday was the second day of bitter cold in the Midwest. On Monday, Chicago saw a record low of minus 16, and Quincy, Ill., tied a record at minus 9. Wind chills across the Midwest were 40 below and colder.

Calculating for the wind effect, Comertown, Mont., saw minus 63 and Rolla, N.D., saw minus 60 wind chills.

Katie Stoll, 34, of Des Moines ventured outside Tuesday morning after staying home the day before. She treated herself to a warm cup of coffee before heading downtown to work at a financial services company.

Temperatures were expected to climb to double digits by Tuesday afternoon — significantly warmer than Monday morning, when temperatures across Iowa were in the negative double digits and wind chills dipped to between 30 and 50 below zero.

"I just hibernated," Stoll said. "I'm already thinking about summer; that's how I get through it."

The South was not immune to the cold. In Pensacola, Fla., the animals housed at the Wildlife Sanctuary of Northwest Florida survived a freezing night without incident, said sanctuary director Dorothy Kaufmann. But Tuesday night's low was forecast for 21 degrees. "The big issue right now is that the water dishes are frozen, so the staff is heating water in the microwave," Kaufmann said. "We're going to stay pretty busy."

Contributing: William M. Welch, USA TODAY; Jennifer Edwards Baker,The Cincinnati Enquirer; Jens Manuel Krogstad, The Des Moines Register; Jeff Montgomery, The (Wilmington, Del.) News Journal; Meghin Delaney, pressconnects.com; The Pensacola News Journal staff.