Richard Barry meticulously searched the ruins of a Paradise mobile home park for things he wished he would not find — bones or teeth, any signs of life lost in the devastating Camp Fire.

Barely visible within a pile of dust, Barry noticed what appeared to be a small skull. His mind raced with a sickening thought: Oh my God, it’s going to belong to a child.

But it didn’t. The skull belonged to an antique porcelain doll left in the rubble.

“At the time we didn’t know what we were looking for,” Barry said. “We knew we were looking for human remains, but I don’t think anybody was prepared for what that meant. The fire burned so intensely that the only thing that was left was calcium, or human bone.”

The hundreds of search and rescue volunteers who responded to the Camp Fire — and many others involved each year in California’s natural disasters and mass tragedies — come from diverse backgrounds, including teachers, doctors, city employees and retired law enforcement professionals. When the Camp Fire started, they took time off from their day jobs to carry out one of the most difficult tasks in the fire zone: finding victims.

Barry is a retired orthopedic surgeon turned unpaid search-and-rescue volunteer. Searching for human remains is a far cry from the sterile operating rooms of his professional life, where order and reason were the rule.

Like other volunteers unaccustomed to confronting the widespread tragedy of a wildfire, he is trying to find ways to cope with witnessing firsthand the results of the devastation. The process is as long and complicated as it is varied among the individuals.

The Camp Fire burned one football field per second when it ignited on Nov. 8, and ultimately destroyed 18,793 buildings, including 13,972 homes.

Butte County officials knew they didn’t have enough resources to handle the destruction so they put a call out to the state’s Office of Emergency Services. Counties including Alameda, Solano, Marin and San Francisco sent firefighters, coroners and search and rescue workers to deal with the carnage.

“The devastation is difficult to describe,” Barry said. “It’s so complete and so broad. The emotional stress in something like this is like water in a bucket — it has to come out.”

The Camp Fire was Barry’s first assignment for the Solano County search and rescue team since completing training last summer. He went to Paradise the day after Veterans Day, worked two 17-hour shifts and returned in time for Thanksgiving.

“I was pretty quiet,” Barry said about coming home. “It was a lot.”

To deal with the stress, Barry went on hikes near his Vacaville home, talked with his fellow volunteers and spent Thanksgiving commiserating with his family members about what he saw.

Kevin Ives, Solano County’s assistant search and rescue coordinator, said his team of 38 volunteers includes teachers and city employees who took time off from work.

“You have somebody whose day-to-day job is clerical and they’re stepping forward to do this, you want to make sure they are safe and they go on with their life after,” he said, adding that both during and after an assignment, he stresses the need for drinking water, talking to people and staying away from alcohol.

“Don’t hide out,” Ives said.

The toll isn’t any easier for those like Andrew Rateaver and his wife, Alyson Hart, who have a spent a career responding to disasters, including the Oakland hills firestorm that killed 25 in 1991, the 1989 Loma Prieta earthquake that killed 63 people and the Wine Country fires that killed 44 in 2017.

After they both retired in April from the Berkeley Police Department, they began volunteering with Alameda County’s search and rescue team.

The couple, both 55, were at their cabin in Lake Tahoe when fire broke out in Butte County. They were planning to stay until the first snow fell. But when they received word on their phones that the blaze was worse than anyone had predicted, they knew it was time to pack up.

Hart got their English shepherd, Gig, a cadaver dog, ready. They found a sitter for their other two dogs, checked their gear and were sent to the Camp Fire the next day.

“Your first thought is the devastation, ‘Whoa, this is pretty big,’” Rateaver said. “Then it’s, ‘OK let’s get to work.’”

Rateaver was in charge of teams of search and rescue workers who went through hundreds of acres with shovels, poles and rakes, scouring the area for human remains before they could clear the area for repopulation.

“I know what I felt in the (1989) earthquake and the (Oakland hills) firestorm from years past and how outside myself I felt,” Rateaver said. “Some of my people now, who are very young and haven’t been exposed to this, are feeling that way now. I was very concerned for them.”

He made sure the volunteers were checking in with family and friends who might have been affected by the wildfire.

After working as cops for nearly 30 years, Rateaver’s and Hart’s instincts are to stay strong. But sometimes, the emotions get to them, too.

Not long after the Tubbs Fire raged through Santa Rosa, the pair were searching through properties for victims when Rateaver discovered a cat hiding in a shallow pool of water. The cat was badly burned. Rateaver carefully picked up the feline before handing it to another officer, who had the cat taken by helicopter to a vet.

“Whatever is defenseless, we will go out of our way for it, and that I think is a vulnerable spot for us,” he said. “I moved hell and yonder for that damned rascal.”

Despite their training, the couple know they have to find ways to take care of themselves, too — whether it’s eating comfort food or watching their favorite TV show, “Outlander,” a drama about time travel.

And at least they have each other.

“Having Andrew, that’s a big piece of it,” Hart said. “You get somebody that gets it. If something is tough, you can talk about it real quick and then it’s done.”

Rateaver smiled at his wife, “She’s the tough one in the family, I’m the one who will go to pieces.”

Sarah Ravani is a San Francisco Chronicle staff writer. Email: sravani@sfchronicle.com Twitter: @SarRavani