The ferocious February cold snap turned snowy overnight, dumping one to two inches of crisp, dry flakes -- and a host of school closings -- on a region already struggling with bitter temperatures, broken boilers and burst water pipes.

Most area school systems closed for the day{vbar}, while officials in the District, Arlington, Alexandria and Falls Church City said public schools would open two hours late. Several D.C. schools were without heat; students from those schools will be shuttled to classrooms in other buildings.

The snow was light and crunchy -- a "sweepable snow," in the words of one television forecaster. Cars could be cleaned off easily, with a sweep of a brush or a gloved hand.

As of 6 a.m., highways and most major roads were clear, but many neighborhood streets were slick and icy. The snow-coated trees and buildings were like so much spun sugar. A few flakes still danced through the air.

Forecasters said temperatures would remain below freezing today, with a high of about 30 degrees. The mercury will continue to creep up, with a high of 33 degrees expected tomorrow, 34 on Friday and 37 on Saturday.

"It's going to stay cold for the next week, at least," National Weather Service meteorologist Chris Strong said. The average temperature range for this time of year is 28 to 45 degrees, he added.

But 30-degrees plus could seem downright balmy compared with the 10-degree temperatures recorded at Reagan National Airport yesterday morning, the coldest day so far this winter. After touching that low point at 7:34 a.m., the temperature began to climb, and by afternoon it reached 27.

Winds yesterday reached 22 mph, just below Monday's 24 mph. Ten to 15 mph winds are expected today.

The extreme cold has caused a record demand for power, triggering a mechanical problem yesterday that cut off heat to about 600 houses along River Road in Potomac, Washington Gas officials said.

As utility workers went door to door to relight gas pilot lights in the homes, Montgomery County officials set up a shelter at the Potomac Community Center.

There were no takers. The Red Cross "stood down" about 9 p.m. and was packed up by 10 p.m., spokesman Marcus Rosano said.

Many of those affected by the shutoff apparently followed the example of Elizabeth Silva of the Potomac Manors subdivision. She said her family intended to tough it out at home, bundling up in layers.

"I grew up in Connecticut. It's really not that bad. We had a wood-burning stove in my house growing up. It got cold. But it always got warm again," she said.

In the District, mental health officials sent staff to talk to 42 homeless people who refused shelter, trying to get them indoors, said Debra Daniels, of the city's Department of Human Services. Nine vans searched for homeless people, up from Monday's six. Officials urged people to call the city's hypothermia hotline at 800-535-7252 if they see anyone in need of shelter. "We're trying to save lives," Daniels said.

About three dozen D.C. public schools had heating problems yesterday, said spokesman John C. White. School officials moved students into heated areas of the buildings, he said.

H.D. Woodson High School in Northeast will be closed all week while crews repair broken water pipes, White said. Simon Elementary and Johnson Junior High schools will also be closed today because of heating problems, White said. Students from Woodson will be transported each day to Evans Education Center; students from Johnson will be taken to Turner Elementary and Malcolm X Elementary; and students from Simon will be bussed to P.R. Harris Education Center.

At J.O. Wilson Elementary School in Northeast, children arriving for classes yesterday learned that the heating system in half of the building was not working.

Principal Cheryl Warley was undaunted. She moved the kids -- more than 100 preschoolers, kindergartners and fifth- and sixth-graders -- to the other wing, where the heating system was working.

But then a pipe burst and the boiler shut down a few hours later, causing temperatures throughout the school to plummet. Two fourth-grade classes were forced to share a classroom. The cafeteria's cooks bundled up in coats and hats to prepare chicken patties and string beans.

Regina Weathersby, a sixth-grade teacher, said the school's heating system has been breaking down for weeks. On some days, she said, it's so frigid that teachers allow female students to wear pants under the dresses they wear as uniforms.

"We grin and bear it," she said. "We do calisthenics. We move around a lot."

By early afternoon yesterday, teachers and students were in coats and scarves, and administrators were scrambling to call parents to pick up their kids.

In Northern Virginia, there were numerous reports of frozen or broken pipes. About 20 residents of a Leesburg apartment complex were moved to other units as a result of "significant water damage," said Mary Maguire, a spokeswoman for Loudoun County Department of Fire, Rescue and Emergency Management.

Dominion Virginia Power anticipated that the day would set a record for power usage. Pepco, which supplies power to the District, also broke its record for winter usage yesterday morning -- a record that had been set the night before.

In Alexandria, Trish Grieger and Sara Dina of Fairfax County ushered their daughters into an Old Town cafe after visiting historical sites as part of their home-schooling. As they warmed their hands around cups of hot chocolate, Grieger and her daughter Rachael, 9, who moved recently from Australia, marveled at their first East Coast winter.

Only three of Dina's four daughters had braved the outing. A fourth had stayed home, too afraid to face the cold.

"My dad said we had to wear six layers," said Catherine Dina, 11, pointing at her torso, which was clad in sweater upon sweater.

In Potomac, three schools -- Potomac Elementary, St. Francis and Bullis -- dismissed students early when they lost heat. Many area private schools were closed today.

Some nursing homes in Potomac also were affected, including one that the gas company was powering with a truck in the driveway, said Timothy Firestine, Montgomery's chief administrative officer.

Diana Conway, president of Potomac Elementary's PTA, said her 12-year-old son, Will, a student at Hoover Middle School, was spending yesterday afternoon hunched over his computer. "He is sitting very still, and he's not saying anything," Conway said. "He's got his winter coat on."

Will and his 11-year-old sister, Catherine, were mostly annoyed that their school didn't close early, their mom said. "They wanted to know why they didn't get out of school, too," she said.

Conway said her heat was restored by Washington Gas about 7:45 p.m.

Staff writers Tara Bahrampour, V. Dion Haynes, Raymond McCaffrey, Robert E. Pierre, Candace Rondeaux and Martin Weil contributed to this report.