Kevin Kuhn knew he wanted to be a firefighter when, as a boy, he watched his father Thomas, a San Francisco firefighter and his hero, win an award for saving a life.

He just didn't know it would land him shirtless on the pages of the first national firefighter charity calendar, Nation's Bravest: Firefighters Unite 2012.

Kuhn, a San Francisco native who moved with his family to Mill Valley when he was 7, is Mr. December.

"My dad loves to make fun of me," says Kuhn, who has been with San Francisco Fire Fighters Local 798 for 61/2 years. "He talks about how they didn't have calendar in his day; they were 'real men.'"

In the calendar a ripped Kuhn stands topless in his bunker pants, his red suspenders hanging down by his sides, in front of the San Francisco skyline. It is pure beefcake, he readily admits.

"Oh yeah, but it's all in good fun. I'm having fun with it. I make fun of myself, too," says Kuhn, who was happy to pose half-naked to benefit Local 798's toy program, the oldest and largest organized toy program in the country. "I don't really think of myself as a model."

Kuhn was asked by the union to apply when it heard the calendar organizer was looking for someone to represent California and that the calendar would raise funds for charity.

The 6-foot-4 Marin Catholic graduate stays fit by playing basketball and running Marin's trails as well as time at the gym.

"I work out a lot, I stay healthy. I think it's a big part of our job," says Kuhn, whose parents still live in Mill Valley. "I love Marin, I go back all the time."

Next week he and the other firefighters will be in New York City for the last fundraising event of the year, a "Snag Yourself a Hero" mixer on Dec. 15 with "Real Housewives of New York" star Sonja Tremont-Morgan. But Kuhn, 30, isn't snaggable anymore; he got engaged a few months ago and is planning to wed next October.

"She's been really supportive," Kuhn says of his fiancee. "She knows it's for a good cause."