Coldest Air Mass in 4 Years Blankets Much of Nation : Winter: Frigid conditions extend from Rockies to the South and the Northeast.

The uniform of the day from the northern Plains to the Northeast was clothes, clothes and more clothes Saturday as a river of North Pole air flowed across much of the nation east of the Rockies.

It was the coldest air mass to invade the United States since December, 1989, the National Weather Service reported.

“I have on my normal underwear, Duofold long johns, a turtleneck, a second pair of long johns, a sweat shirt, sweat pants, a two-ply wind breaker, a 20-year-old fake fur jacket that is about the warmest thing I own,” said Alice Masters of Mt. Vernon, N.Y., as she caught a train into New York City. She also wore two scarves, a beret, earmuffs, gloves and boots.

The cold was nothing new to places like International Falls, Minn., which hit 34 degrees below zero on Saturday, or North Dakota, with lows of 33 below at Grand Forks and Fargo.

In northeastern Minnesota, an unofficial observer at Roseau reported a low of 46 below, weather service officials said. On Chicago’s lakefront, wind off Lake Michigan drove the windchill to 62 below zero.

The cold air mass extended from the western Plains to the East Coast and well into the South. Jackson, Ky., chilled to a record zero, and Asheville, N.C., bottomed out at a record 7 degrees. At North Carolina’s Grandfather Mountain, the low of 9 below combined with winds gusting to 75 m.p.h. for a windchill of 85 below zero.

A low of 32 below at Watertown, N.Y., greeted about 125 members of the Army’s 10th Mountain Division returning from Somalia, where temperatures were in the 90s, to their home base at Ft. Drum.

“I thought my lungs were going to crystallize,” said Lt. Col. Chuck Sardo.

Homeless shelters scrambled to provide extra beds and meals.

New York City agencies reported that 6,344 people spent the night in city shelters, short of the capacity of 6,564 beds. Philadelphia’s “code blue” emergency rule was in effect, allowing city workers to legally force people into shelters.

Power lines that snapped in the cold caused scattered power outages; 20,000 customers were without electricity for part of the night in Tennessee.

On frozen Gull Lake near Brainerd, Minn., an estimated 5,000 people paid $35 per line per hole to participate in the fourth annual Brainerd Jaycees’ Ice Fishing Extravaganza--despite a temperature of 37 below.

“You’ve just got to know a die-hard fisherman. They’ll do about anything,” said spokeswoman Susan Hadrits. The charity event also had the incentive of more than $100,000 in cash and prizes.

Four heated tents were set up on the ice to let contestants warm up, and there were stands selling pizza, barbecue ribs and chili. “There’s beer available, but I don’t know how many people are going to be drinking that,” Hadrits said.