Check the temperature as the sun sets Sunday and the Inaugural Balls welcome women in gowns and men in tuxedoes. Freezing temps might cause problems for ladies in stiletto heels but will be good news for homeless families.

Because in the nation's capital, the city is mandated by law to provide shelter for families if the thermometer drops below 32 degrees, which triggers the hypothermia threshold.

If it falls below freezing the night before Barack Obama is inaugurated, will the city put a roof over every homeless family?

"Yes," Department of Human Services Director David Berns tells me. "As long as it comes to our attention."

But if it's above freezing, moms with infants might be searching for shelter, as the inaugural revelers are searching for Champagne.

Homelessness used to be the predicament of single adults.

"Now the economy has made it more difficult for families," Berns says. "They're staying with relatives, couch surfing, wearing out their welcome -- and coming to us. It's happening all over the country."

The number of homeless families in the District has gone up 75 percent since 2008, according to the Community Partnership for the Prevention of Homelessness. There were 2,688 members of homeless families in 2011; last year that number was 3,187.

Sadly and ironically -- even tragically -- if the temperature does not fall below freezing, and the hypothermia alert is not met, homeless families might have to spend the night on the street, because the city does not have to house them, unless it has space. And if the city runs out of space on inaugural night, mothers with toddlers might be out of luck.

"Families are getting turned away," says Jean Michel Giraud, executive director of the Community Council for the Homeless at Friendship Place. "They are not being sheltered. It seems to be acceptable. It's not."

Scott McNeilly, a staff attorney with the Washington Legal Clinic for the Homeless, says mothers with young children have been bunking at bus stations, taking cheap round trips to New York, falling asleep in hospital emergency rooms.

D.C.'s Berns says the city is on the verge of finding solutions for families without homes. Rather than having to force them into hotels and motels, as the city did last year, his agency is finding permanent, subsidized housing -- and jobs and counseling. Last month, he says, the city found permanent homes for 60 people. "And we are addressing the root issues," he says, "not just building more shelter beds."

The bad news is that Berns estimates that 6,000-7,000 families in D.C. have housing that is "very insecure." If they wind up on the street, homelessness could be a problem well beyond the inaugural festivities.

Harry Jaffe's column appears on Wednesday. He can be contacted at