In mid-May, the supervisors at one Department of Children and Families office sent an unusual request to staff. Employees were asked to work in shifts in the office, covering nearly every hour of the day for a week — with at least two on premises overnight, according to an e-mail reviewed by the Globe.

That last part was crucial. A teenager in DCF custody needed a place to stay, and the office north of Boston appeared to be the best option.

“There was nowhere to place her,’’ said one social worker in the DCF office, who asked to remain anonymous out of fear of retaliation from the agency. At the last minute, the worker said, staff were able to track down an emergency foster home for the teen. “I’ve worked at DCF for over 20 years. This is the first time I’ve ever heard of boarding [a child] in the office. Ever.’’

As Massachusetts’ strained child welfare system emerges from the pandemic, attorneys and staff say the longstanding challenge of finding beds for at-risk children is reaching new levels of desperation, stressing DCF in ways they say they have rarely, if ever, seen.

Staff in at least three offices in Eastern Massachusetts have been forced at times to draw up plans to house children on site, going as far as to schedule staff or solicit volunteers in case a foster home can’t be found, according to social workers and e-mails reviewed by the Globe.

Supervisors in Lowell were searching in mid-May for two employees to stay overnight in the office with a 16-year-old, “should it be needed,’’ according to an internal e-mail. In DCF’s Malden office about three weeks ago, staff prepared for a 9-year-old child with autism to sleep there, said one social worker in Metro Boston.

“They already had the air mattress there,’’ said the worker, who spoke on the condition of anonymity.

In each of the cases, staff ultimately found other accommodations. But the potential has unnerved veteran social workers, who say the DCF offices, which lack showers or a full kitchen, are not equipped for even temporary stays.

Social workers say group homes, and other settings they’ve long considered safety valves when a foster home isn’t available, are filling up, creating unusually long wait lists. Some group homes themselves are struggling to retain staff, who may be looking elsewhere for better pay, said Peter MacKinnon, president of SEIU Local 509, which represents DCF social workers but also some who work in contracted group homes.

Meanwhile, DCF’s efforts to grow its list of foster parents, long a chronic challenge, appear to still be falling short of demand. The agency says it’s added a net gain of nearly 290 foster homes since 2017. But it weathered a dip during the pandemic, and as of this month, there are currently 2,227 statewide, about 200 fewer than the agency had at the beginning of 2019.

Those figures do not include so-called kinship homes, where a foster child stays with a relative.

State officials acknowledge the pandemic has thinned the number of beds in group homes, though they expect availability to rise as COVID-19 infections continue to drop. The agency said it also keeps a real-time directory of emergency foster homes that staff can turn to on nights, weekends, and holidays.

DCF officials did not directly address questions from the Globe about the reports that its staff have weighed having children sleep in the area offices.

“DCF is committed to ensuring the safety and security of children in our custody,’’ said spokeswoman Andrea Grossman, adding that it has 29 recruiters focusing on bringing in more foster parents “so there are enough safe homes to meet children’s specific needs in the communities where they live and go to school.’’

The current strain is so acute, however, DCF staff have told lawyers who represent children or said in court that the agency is simply out of options, according to two attorneys.

“I was informed by DCF that they had no open beds for females across the state,’’ said attorney Debbie Freitas, who represents children in the child welfare system with her sister and law partner, Cristina Freitas. DCF officials delivered the message three weeks ago after one of their clients, a girl in DCF custody in the northeast part of the state, bounced among three locations in a matter of days.

“When she called me, she was almost finished blowing up an air mattress in the DCF office,’’ said Debbie Freitas. A short time later, Freitas said the girl called back with an update: Staff ultimately found a temporary home for her.

“The lack of foster homes has been a chronic issue,’’ Cristina Freitas said. “But the lack of any placement at all has come over the last month.’’

DCF has long struggled with finding regular, stable places for children in its custody. In 2019, nearly 27 percent of children endured three or more moves within their first year in DCF care in Massachusetts, the second-highest rate for any state in the country behind Tennessee, federal data show. (DCF officials say that’s improved to 19 percent in the year between March 2020 and March 2021.)

The Globe reported the same year that workers regularly crisscrossed the state with kids in the back seats of their cars, waiting on word of a foster parent with an open bed, as the agency juggled more than 9,200 children in foster care.

The number of children in placement dropped to roughly 8,400 in July 2020, but it has remained stubbornly level since, ticking up to 8,436 in April, state data show.

Many factors may be feeding into the current shortage. Court petitions filed by DCF to remove children from their homes are inching back toward pre-pandemic levels, increasing for the first time since Governor Charlie Baker declared a COVID-19 state of emergency in March 2020.

There were 819 petitions filed between March and May of this year, an increase of more than 50 percent from the same three-month stretch in 2020. There were 774 during that span in 2019.

The state’s opioid epidemic also continues to rage, splitting families and pushing children into the child welfare system. Combined with the stress of the pandemic, it has made the cases coming to social workers even more challenging, said MacKinnon, the union president.

“It’s a perfect storm,’’ he said. “You have caseloads going up, the intensity of the cases coming to DCF’s attention is getting worse, and that, coupled with the shortage of homes, you don’t have enough placements.

“It all starts with that lack of foster homes,’’ he said. “But it’s rippling through the system.’’

The current shortage is manifesting in other ways. Joy Hotchkiss, an attorney who works in Middlesex and Essex counties, said a teen boy she represents was placed for two nights in a Department of Youth Services facility, which is a secure, locked building that houses juvenile delinquents or youthful offenders. The teen, however, had not been committed to DYS, Hotchkiss said.

DCF officials said any DYS placement is court-ordered.

“It’s not a placement. It’s jail,’’ Hotchkiss said. The teen was later released to social workers in DCF’s Haverhill office. “They don’t have beds. And that’s their response [in court]: ‘We don’t have any beds, judge. There are no openings anywhere.’ ’’

It has left some workers feeling defeated. As pressure grows to find emergency homes, one social worker in the northeast part of the state said workers often only have time to meet DCF’s minimum guidelines for placing a child, raising fears that “something can get overlooked.’’

“There are a lot of nights that you don’t feel good when you go home,’’ said the employee, who spoke on the condition of anonymity out of fear of retribution from DCF. “And when you wake up, it’s, ‘Is this going to be the night when I’m going to stay at the office with a kid?’ There’s always that fear.’’

Matt Stout can be reached at matt.stout@globe.com. Follow him on Twitter @mattpstout.