BAGHDAD, Iraq (CNN) -- Under a huge tent just outside the medical unit at Camp Liberty, shielded from the blazing sun, soldiers watch and cheer as two men at a time get their heads shaved. Clumps of hair fall to the hot sand below.
Maj. Stephen Roberts, a pediatric oncologist, set up a St. Baldrick's cancer fundraiser on his new base in Iraq.
But they're not just fighting the Iraqi heat. They're showing solidarity with sick kids they don't even know.
It started with a dare on St. Patrick's Day 2000, when two guys shaved their heads to support children with cancer. Thus was born the St. Baldrick's Foundation. In eight years, the awareness and fundraising organization says, events have taken place in 18 countries and the United States, "raising over $34 million and shaving more than 46,000 heads."
Maj. Stephen Roberts knows a lot about bald heads. He's a pediatric oncologist at Walter Reed Army Medical Center in Washington. And he's seen a lot of his young patients lose their hair to chemotherapy.
The kids he guides through treatment don't seem fazed by it. "They're just amazing, inspiring kids," Roberts said. "They're going through something more difficult than most of us can imagine and they do it with a level of grace and strength that I don't think I could match."
This year, Roberts planned to participate back home in Washington, but he deployed to Iraq. So he organized the shearing on the base. Watch the soldiers getting shaved to help kids with cancer »
Many of the the soldiers who stepped up on this hot spring day have been touched by cancer in their families. Sgt. Sean Bonney, who's sporting a thick growth of gray hair soon to be shaved off, has a cousin who had childhood cancer and survived. He says he'll be thinking of her. "They're in the fight of their lives," he said. "I just want to encourage them to hang in there and fight on."
Spc. Krystyne Wilson, a medic, says her uncle died of leukemia before she was born. "I'll never get to know my uncle," she says, "and maybe if there were things like this going on back in those times then he could be able to be here today."
Back in the Washington suburbs, the other half of Roberts' fundraiser is taking place in an Irish bar. Doctors, parents, friends, supporters -- and several little patients -- gather as more volunteers go under the razor.
Justyn Exman, 5, is one of those doing the honors -- guided by a professional barber. He looks like he's having fun, as he plows through the man's hair like a suburban father mowing the grass.
Nearby at a table, 6-year-old Briarra Manis is drawing a picture with crayons. Last year she went through treatment and her hair is growing back in an adorable pixie style. As she watches the adults on stage she says, "They act funny." But, she adds, "I think they want to help me."
One young girl with a long ponytail sits in the chair, ready to face the scissors. She's donating it to an organization that makes wigs for cancer patients.
Back in Iraq, the female soldiers can't participate; Army regulations don't allow shaved heads for women. But that doesn't stop them from cheering the guys on -- or making donations.
Roberts says research into childhood cancer has made an astounding difference. "Most of the diseases we treat used to be a death sentence," he said. "In the 1950s, 80 percent of kids with cancer died. Today, 80 percent will be cured forever. In the early 1970s leukemia was 100 percent fatal; now 90 percent of kids are cured."
Roberts is in the chair. The barber starts from the bottom and moves up. Big swaths of white scalp gleam in the desert sun. "I'll save on the shampoo," he says. But he'd better load up on the sunscreen.