It was as if a lifetime’s worth of experience had led 52-year-old Stephen Weltsek to one moment last winter: In an East New York homeless shelter bathroom a young man passed out with a needle in his arm and Weltsek, coming upon him, knew just what to do.

It was a drug overdose, and Weltsek was equipped to help, something advocates are urging for more New Yorkers as the city confronts an opioid crisis.

Weltsek’s knowledge came from difficult experience. He had dropped out of high school to become a plumber in the 1980s but soon, “the drugs got to me,” Weltsek says. He left plumbing behind.

What did he do? “Anything and everything except work,” he says. Sometimes he’d steal the expensive scales and meat slicers from delis, to sell on Delancey Street.

He waited along with other users at Lower East Side drug markets and shooting galleries with Manhattan names: The Office. Executive. He sold drugs and used them. He did several short jail stints, until 2010, when he got caught making a sale and got more than three years.

He was in and out of homeless shelters and drug programs. “He always got pulled back in,” says his sister, Melissa Luzopone, 48, who has tried to help Weltsek with paperwork and the like when she can.

But somewhere along the way, Weltsek started carrying a small zipper-closed bag holding naloxone, the lifesaving medication that can reverse an overdose.

The opioid epidemic is a city problem too

Kits like Weltsek’s have been distributed by city officials and health care workers as overdose rates have leaped — increasing for six consecutive years in NYC and driven by the ready availability of the hyper-powerful semi-synthetic opioid fentanyl, according to the 2017 Mayor’s Management Report. Over the last two years, more than 2,000 people have overdosed in the city. In 2016, there were more fatal overdoses than the number of homicides and car accidents combined.

In March, Mayor Bill de Blasio launched an effort to combat the opioid issue, focusing some attention on NYC’s homeless. According to a Department of Health and Mental Hygiene report covering fiscal year 2016, overdoses were the leading cause of death among homeless individuals, accounting for more than 50 deaths.

That’s what Weltsek was up against that winter morning in an Atlantic Avenue shelter. He had used his kit once for a friend around 2009. This time he only knew the young man’s nickname. But he saw the motionless body and screamed for help, ran back to his bed for his kit. He returned prepared, but a security guard stopped him.

Time is important in overdoses. Weltsek remembers yelling at the guard to let him through. But the guard wouldn’t let him pass: Weltsek says he heard a manager tell the guard over a walkie talkie that he shouldn’t be admitted, that it wasn’t clear what he was going to do. Blocked, Weltsek was forced to wait for a nurse to arrive, some long minutes later with her own kit, ready to revive the young man. By that time it was too late.

A nightmare that could have been avoided

“I shut down,” says Weltsek.

He says he has dreams of the man, as if they’d known each other all their lives, but then the man’s face changes and asks why Weltsek let him die. Weltsek wakes up sweating, as he does thinking about other real nightmares of his past — being in solitary, for example, wondering whether anyone would unlock his door if a fire occurred.

Weltsek wants his story to make a difference. Since the death at the shelter, he has started working with the nonprofit advocacy group Vocal-NY, which has helped him find longer-term supportive housing and advanced his story to push for legislative changes.

The group is rallying at City Hall Wednesday to urge passage of City Councilmember Ritchie Torres’s bill mandating more training for homeless service workers regarding overdoses. The bill may be coming up for a vote within weeks, though a sticking point appears to be a proposal to extend naloxone training to shelter residents. There is some debate on how many residents the training should be required to reach, with the Council pushing for more.

Isaac McGinn, Department of Homeless Services press secretary, says that every DHS shelter has staff trained to administer naloxone and some residents have been trained through outside organizations. In 2016, DHS said staff saved 94 lives using naloxone.

Weltsek hopes more shelter residents will carry the kit, and especially those who are getting high or are near people who do. They could avoid his nightmares, and save a life.

“We’re treated like society’s parasites,” he says. “But we could be first responders.”