When he finishes a full day at work, Cornell Chappelle searches for weary faces, hungry eyes and scantily clothed people living on Washington's streets.

But it isn't easy trying to prevent people from freezing to death. "A lot of these guys don't want to come in," Chappelle said Wednesday evening when temperatures were in the 20s. "A lot of the guys had what they consider to be bad experiences in the shelters. They can't deal with that structure."

Chappelle runs a city-owned shelter for the homeless on Irving Street NW. When temperatures begin falling in the evening he joins several other city workers and Council of Churches of Greater Washington employes who drive two vans. They look on grates, along sidewalks and under overpasses for homeless people who may be freezing.

Last Friday Mayor Marion S. Barry announced that the city would begin the program to try to encourage the homeless to come in from the cold.

"Our intention is to get as many people as we can into a warm, safe environment and then begin impacting on their needs," Chappelle said.

Each van receives radio messages relayed from police and citizens on the location of homeless people who may need help.

Chappelle rode with Eric Easter, who joins the program one or two nights a week and is the spokesman for the office within the D.C. Department of Human Services that operates the van rescue program.

"In the first case, we ask them if they want to come in to a shelter ," Chappelle said. "If the homeless person says yes, they are taken either to the shelter of their choice or to one that has space," he said.

The homeless will be given blankets, boots and surplus Army jackets, donated by the federal General Services Administration, if they are needed, Easter said.

When drivers and their partners, who are called "jumpers," find a homeless person suffering from hypothermia, a lowering of the body temperature, they can radio for help. They can also call if the person appears to be mentally ill.

"That's a judgment call," Easter said. "We call back to base and they call the police."

Easter and Chappelle drove around the city for five hours and handled five cases. They picked up Bob, 32, when they spotted him carrying a bedroll and walking in a grassy area on L Street NW near the Rock Creek Parkway.

Bob declined to go to a shelter but asked for a new blanket and a ride to Lafayette Park.

"I don't mind staying outside," he said. "I feel better. It feels like I'm not cooped up or cramped. I don't know if that makes any sense, but . . . . "

He said he had been living on the city's streets for four years, since he was laid off from his job as an analyst of coastal programs for the state of California.

"Sometimes I think it was a mistake to think I could ever work in an office," said Bob, a tall man with a long dark blond beard, wearing a parka that he said was recently given to him. "I don't have a good explanation, but it was always noisy."

During their tour, Chappelle and Easter took two men from Lafayette Park to shelters and gave each a jacket; responded to calls on two locations but found no one, and aided a 16-year-old South Carolina youth who had been stranded in a bus station for two days with no food.

At 9:30 p.m. Chappelle and Easter turned the van over to James Jackson and Lewis Anderson, both from the Council of Churches.

Jerry Graham, 47, who was found in front of an adult bookstore on 14th Street NW, was fed coffee and a doughnut and taken to the Pierce School shelter for homeless men in Northeast Washington.

At the entrance to the Upper Cardozo Neighborhood Health Center at 3020 14th St. NW, they found a figure slumped in a corner.

It was an intoxicated woman. Men are not supposed to transport women, but with no women helpers available, the two men received approval to take the woman to the House of Ruth shelter in Northeast.

"Being drunk out here . . . pores all open . . . " Easter explained later. "It's certain death," Anderson said, finishing Easter's thought.