In anticipation of temperatures dropping Monday evening far below freezing, local governments and organizations in the DC area are on heightened alert to get all homeless people off the streets, out of the cold and into shelter.

The biggest concern, officials and advocates say, is not just the cold temperatures, but the length of time someone is exposed to them, which can result in frostbite, hypothermia and even death.

The temperatures forecasted for Monday night, said DC Mayor Vincent C. Gray, “can have deadly consequences for those who are exposed to it even for a short period of time.”

In the District, the United Planning Organization’s shelter hotline beefed up staff through the day and has had eight vans out looking for chronically homeless people at what they call “hot spots.”

“Our goal throughout the day has been to try to get as many people off the streets as early as possible ,” said Allison Smith, shelter hotline program manager.

Most nights, when people refuse to come into shelter, for whatever reason, outreach workers hand out blankets, sleeping bags, food and other comfort items, Smith said. “But tonight we’re encouraging everyone to come into shelter.”

In the District, where levels of family homelessness have been sharply on the rise in recent years, all family shelters are already at full capacity, with 413 regular and overflow units filled. So the city has already begun to put families up in local hotels. Already, 250 families are in hotels, city officials said.

The city does have enough capacity at their regular and overflow shelters for 1,346 single men and 426 single women, said Michele Williams, with the Community Partnership for the Prevention of Homelessness.

“Everyone is on heightened alert,” Williams said, adding that outreach workers had been out over the weekend, looking in alleys and under bridges and the places where homeless people are known to gather, to try to convince them to come in off the streets and seek shelter.

“There is certainly a risk for people to be severely injured or to die in these cold temperatures,” she added, “That’s why we’re keeping such a close eye.”

The city also announced that all public buildings would be open for people to come in out of the cold during regular business hours.

In Montgomery County, social service agencies are working with police to seek out homeless residents in encampments throughout the county, said Mary Anderson, spokeswoman for the department of health and human service. Emergency and transitional shelters will be available during the day.

In Prince George’s, the county is opening six warming locations that will be open throughout the day. They are also in the process of restoring heat and electricity to any locations that might have had energy services shut off, said Dee-Dee Bass, spokeswoman for the county’s department of social services. They will also be distributing hats, gloves and blankets to those in need.

In Alexandria, a team of therapists, police, and mental health and outreach workers began meeting at 11 a.m. Monday morning to find the 25 known chronically unsheltered homeless people in the city and get them to come inside. The local Carpenter’s Shelter announced that they would be open and serving meals throughout the day during the cold snap.

Officials in Arlington, too, announced they would keep the emergency winter, which usually closes during the day, open around the clock so people can stay warm.

But Robert Ross, who has been homeless for nine years, knows the DC shelter hotline number by heart, but says he won’t be getting into a van to go to a shelter. Instead, he’ll contact the hotline for some extra blankets to go with his new forest green sleeping bag.

“Hopefully my sleeping bag here will keep me warm,” said Ross, 57, as he pointed to the bag in a shopping cart that was filled with his most-prized possessions, including a container of juice. “I will sleep outside – there’s too many bugs and too many crazy people in the shelters.”

Ross, who was leaving McPherson Square to get a cheeseburger and fries for lunch, said this isn’t the first time he’s been outside in severe temperatures. But because he was “at the right place, at the right time” yesterday on Pennsylvania Avenue where some people were donating sleeping bags and coats, this time in the cold will be different.

And when he gets cold, he has a plan.

“I’ll think of a warm woman,” he said as he tugged at a stain on the collar of his tan trench coat.

Brian Raw said he’ll jump on the green line to Prince George’s County and rent a room for the night. But before he can go, Raw, who has been homeless for five years, must collect at least $15 on the street.

“I move around a lot,” he said. “I try to go in stores and restaurants and pretend I have money or I’m buying food to keep warm. I know how to survive.”

Tom Murphy, of Miriam’s Kitchen, a homeless service provider, said one of their regulars came in Monday morning with tingling hands and asking if he had frostbite.

“Fortunately, he did not,” Murphy said.

Caseworkers spent the day trying to convince the chronically homeless to seek shelter Monday night.

“But in the meantime, we’re working hard to make sure that we have all of the supplies and clothing ready for people who need it,” Murphy said, handing out warm hats, sweatshirts and sweaters all day Monday and distributing 131 sleeping bags over the past few days. “We’re trying to get our hands on handwarmers. And gloves. We really need gloves.”

Washington Post staff writers Robert Samuels and Mike DeBonis contributed to this report