Record Cold Continues to Grip Nation : Weather: Snow and subzero temperatures hit the Southeast. Florida declares an emergency as 18 states see all-time lows.

Killer pre-Christmas cold and swirling snow blasted much of the nation again Sunday, snapping temperature records in 18 states, threatening lives and livelihoods from New England to Texas and aiming some of its most vicious slaps at the vulnerable Southeast.

The blistering chill sent the mercury to zero or below as far south as Alabama, and 50 m.p.h. winds stirred up blizzard conditions in coastal North Carolina, where snowfall up to 13 inches and drifts up to 8 feet were reported.

Florida Gov. Bob Martinez declared a state of emergency in an effort to cope with damage to the state’s citrus and sugar cane industries. Icy conditions forced the closure of Interstate 95 from St. Johns County north to the Florida-Georgia state line, and the going was slow on Interstates 75 and 10 because of ice and abandoned cars.

Below-freezing temperatures were reported in all but four Florida counties, and about 5,000 stranded motorists and homeless people were herded into shelters in half a dozen north Florida counties.

Despite the record cold, 720,000 of an estimated 2 million homeless men, women and children were expected to spend Christmas Eve and Christmas Day without shelter, said Peter Smith, president of Partnership of the Homeless, a private shelter network in New York.

In Atlanta, 5,500 volunteers prepared to set tables and hand out gifts for 40,000 of the city’s less fortunate residents.

In Boston, the mood at the Shattuck homeless shelter was “festive and jolly” Christmas Eve, as the homeless gathered to watch a football game between the New England Patriots and the Los Angeles Rams, shelter coordinator Bill Doyle said.

Caterers and individuals donated hot food throughout the day, with new deliveries every 15 minutes, Doyle said.

New Yorkers planned to feed the city’s estimated 82,000 homeless people on Christmas Day at various shelters around the city.

In Texas, where four cities hit record lows Sunday, the bitterly cold air has triggered fears of a repeat of the Christmas freeze of 1983, which destroyed more than 50,000 acres of citrus trees in the Rio Grande Valley.

An electric power emergency across Texas eased as temperatures began to warm in the western portion of the state. Houston Lighting & Power had lost five of its 12 generating plants because of ice problems Saturday and lost service to 157,000 customers. The utility said only about 3,000 customers were without power Sunday morning.

Mississippi activated the National Guard to help the city of Jackson--shivering in 6-degree cold--cope with a frozen intake pipe in the Pearl River that cut off water to 250,000 people. Authorities said they might use explosives to break up the ice jam that caused the blockage.

The most frigid official reading Sunday in the 48 contiguous states was 26 degrees below zero at Houlton, Me., the National Weather Service said.

Successive waves of arctic air and accompanying snow and ice storms have been responsible for at least 92 deaths in the United States since Dec. 15.

At least 58 cities in 18 states reported record lows early Sunday, many setting new standards for cold for the third straight day. Included were at least 16 cities in Florida, usually a sanctuary from the harshness of winter.