CHICAGO — Mike Wood spent his recent vacation in rural Honduras, visiting Mayan ruins but mostly building latrines and pig pens.

That isn't exactly most people's idea of a glorious week in the sun. But it was thoroughly enjoyable for the assistant high school principal — and he apparently has growing company.

"It's fun to see how 80 or 90 percent of the people live in this world and try to help them out," said the Deer Isle, Maine, resident, who was on a trip organized by the group Sustainable Harvest International.

More Americans are starting to feel the same way about vacations with charitable or humanitarian purposes, where they can build housing or schools, collect field data, or work at a refugee camp, orphanage or archaeological dig.

While the trend is hard to quantify, a wide variety of environmental, medical, nature, children's and other groups as well as churches report that participation in volunteer vacations is on the rise.

Surveys conducted recently by Orbitz, Travelocity and the Travel Industry Association of America confirm that consumers are becoming more interested in vacations with a volunteerism aspect, also known as "voluntourism."

Opportunities that once existed largely with nonprofit activist groups are being adopted by a wide range of travel agencies and tour operators. Sally Brown, who heads the Indianapolis not-for-profit group Ambassadors for Children, said the number of travel organizations of various kinds that offer voluntourism trips has probably doubled in the past three years.

Like the 55-year-old Wood, many of the vacation volunteers are baby boomers, who have the money to spend and the time to donate as they edge closer to retirement. But with inspiration coming from a variety of sources — be it 9/11, Hurricane Katrina or just having more disposable income — participants range from teenagers to retirees. Voluntourism is catching on in college campuses, where many students would rather spend spring break doing something altruistic than carousing.

They don't always have to rough it, either. Ambassadors for Children even offers a "light" mission in which travelers stay at a four-star hotel in Puerto Vallarta, Mexico, and spend three of the eight days visiting an orphanage, library and preschool. That may appeal to a family wishing to make a cultural connection, Brown said, or just those wanting to mix purpose with pleasure.

"Immersion with voluntourism is so much more than you could get by sitting on a beach or on a tour bus," said Brown, a one-time flight attendant who founded the organization in 1998.

Wood, who also is a history teacher, didn't spend much time seeing historic sites on his February trip with Sustainable Harvest International. Founded by former Peace Corps volunteer Florence Reed, the organization addresses the tropical deforestation crisis by providing farmers with sustainable alternatives to slash-and-burn agriculture.

He and his group spent a week in a village without electricity, running water or cell phone reception, sleeping in dormitories or with families. Arising at 6 every morning to a breakfast of beans and tortillas, they spent the days digging holes, pouring cement and cutting wood.

The composting latrines they built fit with the group's focus on sustainable agriculture, since the waste can be a rich source of nutrients for family crops and trees. They also left Wood with a sense of personal satisfaction from all his hard work.

"It's fun, and it gets something done," he said. "You can stand back and say, 'I built two latrines.' Or, if you want to look at it more existentially, 'I've helped people not pollute their land, I've helped people produce compost or make it so they can burn and cook without cutting down their forests."'

It cost him $1,000 for the 12 days, not including air fare. That paid for lodging, food, transportation, tools and "peace of mind," he said.

Dr. Peggy Fuller, a dermatologist, went to Sri Lanka to build houses in 2005 after seeing the magnitude of the tsunami devastation. Taking a sabbatical from her successful practice in Charlotte, N.C., she spent several weeks making and hauling cinder blocks, carting dirt, carrying water and sweeping.

"I probably wasn't much help at all," said Fuller, 47. "I wasn't there very long. But to see the people's faces — they were so happy we were helping them. That's something you don't forget."

Accountant John Witkowski used to take his wife and four children on vacation to national parks or the Caribbean or Mexico. Now the children are grown and they go instead on what is becoming an annual trip to an orphanage in Guatemala, where they and other church members stay in gender-separated quarters at the facility run by nuns.

"This is more draining mentally, but it's much more rewarding," said Witkowski, 54, of Colts Neck, N.J.

Their task while there, he said: "Love the kids" and do maintenance projects while they're in school. Despite the language barrier, he feels he connects with the kids through play, joking around and showering them with attention and affection.

Alyssa Stahl, 37, a bank vice president in Chicago, went to West Virginia with Global Volunteers to help build houses in Appalachia last October after finding the group in an Internet search for groups that do volunteer vacations. She did a lot of spackling and painting, working as a mentor to disadvantaged youths.

She's already planning another trip soon to a Native American reservation in Montana.

"You feel that you're helping people and you're also getting to learn about a different culture, whether it's West Virginia or Tanzania," she said.