For Latiana Holmes, sleep is a precious commodity.

On Fridays, she works until 6 p.m. at Dunkin’ Donuts in Roslindale, then runs errands and cleans for her aunt, for whom she works as a personal care attendant. By 10 p.m., she is on the bus from Mattapan to Northeastern University for her overnight shift as a security guard. She heads home in the morning to sleep for a few hours, then back to Dunkin’ Donuts for a five-hour shift, home to see her 2-year-old son and take a nap, over to her aunt’s house, and then back to Northeastern for another overnight shift.

On Sunday, she gets up and does it all over again — sometimes working more than 70 hours a week.

Holmes, 24, is one of 7 million people across the country who work part time but want full-time jobs. Like Holmes, many of them stitch together multiple jobs to make ends meet, and their schedules can be grueling — sometimes even deadly.

Maria Fernandes, a 32-year-old Massachusetts native who worked at three Dunkin’ Donuts in northern New Jersey, died in August while napping in her car between shifts. She did this often, according to news reports, keeping the engine running while she slept, with a container full of fuel in the back so she wouldn’t run out of gas. But the container overturned in her car, the fumes overcoming her as she slept, in her uniform, in a convenience store parking lot.

As part of a nationwide day of action Thursday, Dunkin’ Donuts workers in Boston held a vigil for Fernandes at the Dunkin’ Donuts across from the State House. Fast food employees, joined by airport and home health care workers, held protests at fast food restaurants in 160 cities Thursday in support of the “Fight for $15” movement that seeks to raise pay to at least $15 an hour, widely considered the living wage.

The owners of the Dunkin’ Donuts franchises where Fernandes worked helped pay her funeral expenses, according to Dunkin’ Donuts spokeswoman Michelle King. Fernandes was a “model crew member,” King said, and was offered a full-time position at one store but turned it down due to scheduling conflicts.

“People are just stretched really thin and they’re having to go to extremes to make ends meet,” said Liz Ben-Ishai, a senior policy analyst at the Center for Law and Social Policy, a public policy group in Washington seeking to improve the lives of low-income people. “Just pausing to try to catch your breath like this woman was doing ended up taking her life.”

Holmes knows something about trying to catch her breath. She lives on the first floor of a three decker in Mattapan with her mother, younger brother and sister, and her 2-year-old son, Michael. After dropping out of high school and getting a GED, she started classes at Roxbury Community College but couldn’t afford the tuition, she said. She started working as a personal care attendant for her aunt, through the service agency Cerebral Palsy of Massachusetts, and earlier this year got a second job cooking, cleaning, and working the register at a Dunkin’ Donuts in Roslindale.

Holmes lost her job there at the end of October after she rushed her son to the emergency room with a rash and missed a shift. Holmes picked up a security job at Northeastern and was rehired by Dunkin’ Donuts a few weeks later.

In her best months, she earns as much as $2,400 before taxes — the equivalent of less than $30,000 a year — but ends up absolutely exhausted.

“Once I get home, I’m sleeping,” she said. Or doing laundry to keep her uniforms clean: aprons and white shirts for Dunkin’ Donuts, scrubs for personal care attendant work, and pants, shirt, and a sweater for her security guard job.

The hard work means Holmes can afford holiday gifts this year. But after helping her mother pay the $1,600 rent, plus utilities, and buying food and diapers, there isn’t much left. If her mother, who is on disability, didn’t provide child care, Holmes doesn’t know what she would do.

Still, she plans to quit the security job so she can spend more time with her son. Holmes recently heard him say, “Excuse me, please,” and realized he was talking in three-word sentences — a development she had missed somewhere between work and sleep. “I felt like a bad mom,” she said, as he toddled around the living room in striped pajamas. “I’m missing out on the growth of my son.”

Holmes has been looking for more stable, better-paying work — applying at UPS, Family Dollar, Lowe’s, Home Depot, and the post office. But proximity is an issue, because she has to rely on the bus to get around. She is also thinking of carpentry training but would have to cut back to one job to work it into her schedule — and find a cheaper place to live.

In the end, she wants to provide a better life for her son and make sure he goes to college. But she worries he might be worse off in the long run if he feels neglected.

“All he sees is me working, working, working,” she said. “I don’t want him to think I picked working over him.”