Every Thursday night you can find Nathan Fields making the rounds of Baltimore's red light district, known to locals as The Block.

An outreach worker with the Baltimore City Health Department, Fields, 55, is a welcome sight outside strip clubs like Circus, Club Harem and Jewel Box.

In the early evening before the clubs get busy, he talks with dancers, bouncers and anyone else passing by about preventing drug overdoses and how to stop the spread of HIV and other sexually transmitted diseases.

Later on, he'll drop into the clubs to check on the dancers who aren't able to come outside, finding out what they might need.

Fields has credibility on The Block that people higher up in the health department don't. "I watch him walk down any street in Baltimore city, and people come up to him, and they know that he is there to serve them," says his boss, Health Commissioner Dr. Leana Wen.

It wasn't always so easy.

Seven years ago, Fields was working with the city's needle exchange program. After a spate of drug overdoses at the strip clubs, the health department brought its needle exchange van to The Block one night a week.

There were hardly any takers at first. People were skeptical.

"They were under the impression that we were giving their information to the police," Fields says. "So that's when I came on board. You know, I'm a great negotiator. Donald Trump can't beat me out."

Fields started with the bouncers. Though a Baltimore native, Fields is a huge fan of the New England Patriots and would often show up in head-to-toe Pats gear. The Baltimore Ravens-loving bouncers hated his get-up, and the football rivalry broke the ice.

Eventually, the sports talk turned more personal. Fields learned that some of the men had girlfriends dancing in the clubs who needed help – everything from condoms to drug treatment. Some women needed copies of birth certificates and other forms of ID in order to get into treatment.

Fields leaned on colleagues in the health department to get the problems solved.

Soon, the clubs doors opened for him. Once inside, Fields saw people needed even more.

"We went into one club, and there were three girls in different stages of pregnancy that were still dancing," he recalls. "We started running it up the chain: 'Hey, we need health care down here — reproductive health care.' "

So in addition to the needle exchange van, the city brought a second van to The Block, one with an exam table and a nurse. Now, every Thursday night, health workers offer needles for exchange, training in the anti-overdose drug naloxone, HIV tests, reproductive health exams, pregnancy tests, flu shots and more other basic health care services.

Fields treats each person coming into the vans like family. He remembers babies and boyfriends and other small details of people's lives.

"The Block is like living," he says. "These relationships, you've got to keep them flourishing."

Quietly, Fields also hands out pamphlets with information about drug treatment. Every so often, he'll mention a new option and encourage someone to check it out. But, it's a soft sell. He doesn't want to drive people away.

"I don't beat a person over the head," he says. "I never badger anybody for fear of them looking at me like, 'Oh, he's an elitist. He forgot where he came from.' I could never forget where I come from."

For nearly 20 years, Fields was a heroin addict. He sold drugs to support his habit and did time in the Baltimore City jail. "I was a predator to my community," he says.

After getting clean in the mid-1990s, he got a job as a recovery counselor. In 2004, he went to work with the Baltimore City Health Department. "The job just gives me a sense that I'm helping to build back what I tore down," he says. "You know, every time I can get somebody to even thinking different or even consider going into treatment, I feel as though I had a successful day."

In spite of those small victories, it's been a particularly difficult year for Baltimore and for Nathan Fields.

Over Memorial Day weekend, the outbreak of violence following the death of Freddie Gray claimed the life of his youngest child, 20-year-old Hassan Fields. He was shot and killed on the west side of Baltimore. His death remains an open case.

Nathan Fields struggles to understand how this could happen to him, given all he's done for the community. He had thoughts of reverting to the person he once was. Then, he came to a quieter place.

"I'm sorry. I can't let this destroy me," he says. "I can't let this turn what my thoughts are about human nature — some good people with some bad people. I believe the bad people have a little bit of good in them too. It's just got to come out."

Thinking about Hassan's death has led him to reflect on his own past.

"I just have to look back on myself and say, I've caused pain. No, I've never done anything as violent as that, but I've got to keep working. I can cherish his memory, I sit down, I look at his picture and think about it, and it just makes me work harder."

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