Zlathro Latev sits on a milk crate inside the K Street entrance to the Farragut North Metro station and stuffs his secondhand trousers with newspapers. When a cold wind blows off the street, the newspapers keep blood flowing to his extremities, he explains.

The last late-night passengers moved through the subway half an hour ago, and Latev, 67, is preparing for sleep. Six men share the cement enclosure. Meanwhile, at other downtown stations, about 20 more people settle in, spreading sheets of cardboard at the bottom of escalator wells and drawing their collars tight on the now still steps.

At 17th and I streets NW, Farragut West, once a popular haven, has fallen silent, its entrance blocked by chain-link gates. The transit authority locks the entrance after the trains stop running and is considering extending the practice to other downtown stations.

For Latev, the consequences are clear if Metro shuts out the homeless: "You freeze and you die," the Bulgarian immigrant said in a thick Slavic accent. "That's it."

As Metro considers building more gates, and as advocates for the homeless fast to dramatize their objections, street people struggle to survive another day. They look fearfully toward the coming winter.

Metro officials said Farragut West's $3,700 chain-link barrier is there to stay -- at least until engineers design a more attractive permanent replacement -- because the people who sought refuge at the I Street entrance left behind an offensive and unsanitary mess each morning. In the six weeks since the gates went up, Metro riders have registered strong approval with the public affairs office, said spokeswoman Beverly Silverberg.

Mitch Snyder, founder of the Community for Creative Non-Violence and Metro's loudest critic, agrees with commuters who say Washington should offer its homeless something better than a subway station floor. But Snyder, who began a water-only fast on Nov. 9, said the sad reality is that subway entrances are the best shelters some people can find.

In interviews during the past three weeks, more than a dozen street people echoed that assessment. The meager protection that subway entrances offer from the cold, the rain and the snow can mean the difference between life and death for some of the District's most vulnerable homeless people, they said.

Throughout the downtown area, that protection is slipping away, and the gates at Farragut West are only part of the reason, street people said. They said the greater challenge comes from transit authority police, who stepped up their efforts to keep the homeless off Metro property in early October.

According to social workers, volunteers who minister to the homeless, and homeless people, many subway denizens have been turned away by the city's shelters, which are generally filled to capacity; others lack the mental wherewithal to seek help. Still others consider escalator wells more congenial than shelters, which they describe as squalid, overcrowded and dangerous.

Long after the rumble of trains has faded beneath the city, a stale, steamy draft emanates from Metro's underground tunnels. Its warmth envelops the men at Farragut North -- until the bitter November wind strips it away.

At the base of the escalators, one man wraps himself in a dirty gray overcoat and slumps against a bag of clothing. His hair is matted, and his eyes are bloodshot.

Halfway up the middle escalator, another man draws his knees into his chest, buries his hands in his pockets, and nods off to sleep. At street level, Latev coughs violently, and the sound echos faintly off the cement walls. Beside him, a white-haired World War II veteran with a grizzled beard nurses a faucet nose, and at the edge of Metro property, two other men shiver silently, gazing glassy-eyed at the passing cars.

Similar scenes unfold at McPherson Square, where shadows conceal huddled figures, and Metro Center, where the odor of human waste and unwashed bodies hangs in the air. Unlike the majority of Metro stations, these three have partially enclosed entrances. When Metro workers lock up the tiled mezzanines, the homeless people claim the outer areas.

Subway dwellers confirmed Metro's charge that some vagrants relieve themselves on Metro property, but they attributed that behavior to a relative few. The options are limited, given that there are no accessible toilets at 2 a.m., they said. Most take care to find a rest room before the fast food restaurants close. If the need arises later, they use an alley, although the risk of being assaulted increases when they venture into the dark.

There is little camaraderie among the men who share concrete quarters. They generally pass the hours before sleep without conversation, preferring the privacy of their thoughts. Those are frequently interrupted.

In a routine repeated again and again each night, Metro police officers escort the trespassers out of a station. The vagrants drift into the streets without resisting. Minutes after the police depart, they straggle back inside.

Despite the hardships, many find subways less forbidding than the shelters intended to ease their plight. They complain that shelters are rife with vermin and disease. More than the roaches or the lice, however, they fear other homeless people bent on theft and assault. Older, weaker people are most frequently victimized and frightened into the cold, according to several men and women who said they have stayed in shelters.

"I'm afraid of the cold, but I'm even more afraid of going into one of those rat traps," said Mark Parker, a burly 24-year-old who has stayed at various shelters, in Lafayette Park and at Farragut West.

"I have what I have here. It's all I have," Parker said, pointing to a sleeping bag and a bundle of belongings. "If I go into a shelter, somebody there will take it from me, and if I try to stop them from taking it from me, they may try to take my life."

Parker said he counted on Farragut West as a fallback in bad weather. He still frequents the station at night -- to express his distress to passers-by.

A red-faced 57-year-old woman who wanders the streets said she stopped going to shelters after other homeless people repeatedly robbed her. Last winter, Florence Woodward made the entrance to Farragut West her nightly residence, she said.

Latev, the Bulgarian emigre, told a similar story. He said he was attacked at the CCNV shelter at Second and D streets NW and vowed never to return. "Over there is all criminals, all alcoholics. Dirty, smelly, no good, lice, everything," he said of the facility, which is undergoing major improvements.

Snyder said "people had good reason to stay away" before the improvements began, but he added that fighting is no longer a problem. Five hundred people currently take refuge at the shelter, filling it to capacity, and scores are turned away at the door, he said.

Some of the people who sleep at Metro stations straddle the line between poverty and destitution, rising out of the gutter and periodically falling back. Others work at occasional menial jobs but never earn enough to pay rent.

However, many more are socioeconomic castaways, chronically removed from the city's mainstream. They include senior citizens, alcoholics, convicted criminals and former psychiatic patients. No definitive statistics exist, but some experts estimate that two-thirds of the District's shifting street population suffer from serious mental illness. A 1985 census counted 6,500 homeless people in the city. Social workers and advocates for the homeless said the actual number runs much higher.

Those who forsake shelters or find themselves shut out live from meal to meal and from resting place to resting place. According to their accounts, their days revolve around food wagons and soup kitchens.

They wait in line for the kitchens to open in the morning and often linger indoors as long as they are permitted. They pass much of the day panhandling or loitering, trying to stay one step ahead of the police. As night approaches, they stake out a place to sleep.

A number of those who now find shelter in the subways said they will roam the city in search of vacant buildings or abandoned cars if Metro drives them out this winter. If all else fails, some plan to avail themselves of the D.C. jail.

Ronnie Banks, a 29-year-old homeless man roused by a Metro worker's "wake-up call" last week, said he will steal as a last resort. Banks said that if he gets away with it, he will buy his way out of the cold, and if he gets caught, "at least I'll be out of the streets for the winter."

"The way I feel about it, I ain't got nothing to lose anyhow," he said.

But homeless people who discussed their contingency plans said they worry about others, especially those who cannot speak for themselves. They predict that a few will freeze in District parks before spring.

"I probably would get by," said 42-year-old David, a former patient at St. Elizabeths Hospital. "But there's a whole lot of people that ain't got the right state of mind to get by."

Dr. E. Fuller Torrey, a research psychiatrist who runs a clinic for mentally ill homeless women, said delusions and psychosis often prevent street people from seeking decent shelter. They may be too confused to confront their predicament, Torrey said.

He was referring to people like the man who said he plans to return to his home on a distant planet before the weather gets much colder.

Torrey assigns most of the blame to the District's "virtually non-functional" support system for mental outpatients and those who have been deinstitutionalized.

"A lot of these guys won't make it through the winter," said Richard Hill, who retreated to McPherson Square during a recent rainstorm. "These people are illiterate. They're sick. They're mentally retarded. They need help bad. Some of them have been staying in that subway since it's been open. They don't have a mind to go and search out another place."