For Dallas Hooten, it is the sense of calm and comfort at the Children's Inn that eases the strain of uncertainty about the unconventional medical treatment he receives.

Over the past decade, Hooten, 19, of Kansas City, Mo., has returned often to the National Institutes of Health in Bethesda for treatment of a disease that suppresses the immune system and makes it difficult for his body to fight off infection. For the past three years, he and his family have stayed at the Children's Inn, a cozy residence tucked among tall pines on the NIH campus.

"It allows me to get away from the hospital," said Hooten, who returned to the inn recently to await admission to the clinical center for a second stem-cell bone marrow transplant. "When I come back here," after a day of treatments and examinations, "I have freedom. I can relax, sit and eat."

Thousands of youngsters and their families who turn to NIH for experimental treatment for life-threatening diseases have found a place of solace at the inn. More than 300 volunteers are there to help bring a smile; a variety of activities--from poetry to bingo--help entertain.

Volunteer Wally Horner, 73, of Kensington, arrives about 6:30 a.m. most days and makes sure there is hot coffee for everyone, fresh milk on the table and cereal in the cupboard. He's there for a cheery send-off and a pat on the back when they board the NIH shuttle for the clinical center and a day of tests and treatment.

Every other Tuesday evening, Horner shows up to call bingo for adults and children.

"I've been healthy all my life," said Horner, a retired government worker who has volunteered at the center since 1991. "I like to help people who are not as fortunate as I have been. Volunteering here makes me completely satisfied."

When families enter the inn through its sliding glass doors, they are greeted by a collection of larger-than-life teddy bears and other assorted stuffed animals. During winter holidays, the lobby, which resembles a ski lodge with its stone-encased fireplace and chimney, is festooned with bright decorations. On Halloween, multiple pumpkins decorate the reception desk, and staff members and volunteers are in costume.

The inn, which will celebrate its 10th anniversary next year, was created by NIH as a place for parents and patients to get away from a medical setting, said Jan Mayes, director of development. "Doctors noticed that at the end of the day, parents were gathering in one of the waiting rooms, eating pizza and talking about their day," she said.

Since it opened in June 1990, about 1,000 patients a year have stayed at the inn with their families and siblings. The children have come from 44 countries and two U.S. territories; some are there for as long as 18 months. The average stay is one to three days, with frequent return trips throughout the year.

There is no charge to stay in one of the inn's 37 hotel-like rooms, but donations are welcome. Families purchase and cook their meals and clean their own rooms. The inn, with an annual budget of $1.2 million, gets about 18 percent of its funding from NIH; the rest comes from private donations and fund-raising. The full-time staff of eight includes no medical personnel or social workers.

"Families come to NIH when they have exhausted all hope and treatment," Mayes said. "NIH is their last hope. The treatment is purely experimental. The families are hoping for a cure while at the same time they are participating in research."

The inn, Mayes said, allows parents and children to form friendships that are not restricted by race, language or economic situation. "These are families in crisis," she said. She recalled one child who lost his hair during treatment. In a show of solidarity, another child shaved his head.

At night, the inn is a beehive of activity. "When they hit the door, they are kids," said Susan Oberlander, special projects and activities director. "They just want to have fun."

In addition to bingo nights--when everybody leaves a winner--there are visits from community groups, including the Capitol Clowns, a troupe that entertains the children; arts and crafts; and an occasional visit from the Harley Owners Group of Montgomery County, which delivers gifts in the summer and at Christmas.

Carla Prudencio, 11, of Cochabamba, Bolivia, and her mother, Ernestina, have lived at the inn for a year. Four years ago, Carla was diagnosed with lymphoblastic leukemia. After three years of treatment in Bolivia, her mother brought her to NIH in 1998, when she had a bone marrow transplant with marrow donated by one of her sisters.

Although her leukemia is in remission, there have been complications. In October, Carla became one of the first people to be treated with a new drug. They would like to return to Bolivia at the beginning of next year.

"We are surrounded by people here" at the inn, said Ernestina Prudencio. "There is much love, and we feel as if we are part of a family."

Added Connie O'Dowd, of Warner Robins, Ga., "If there's one thing the Children's Inn needs, it's to be bigger." Her son, James, 18, is being treated at the clinical center for Ewing's sarcoma, a cancer that appears primarily in children.

James O'Dowd's cancer was diagnosed when he was 14. The disease was in remission for 35 months before it returned, and James came back to NIH and the Children's Inn in February.

O'Dowd began new treatment in March, and there was an "immediate response," his mother said. He went home a few months later but returned in September after tests showed the cancer had spread up his spine.

He is now awaiting admission into trial treatment that is "the first step out of the lab," Connie O'Dowd said. "We don't know what the side effects might be" or whether it will work.

She said she has found a lot of comfort at the inn. "You sit here and see people who are worse off than you are," she said. "You also see successes. The support is great, and the staff is great. I wonder if listening is in their job description."

For Dallas Hooten, who was admitted recently as an inpatient at the clinical center, the next few months of treatment may be tough. His stay in the hospital could be as long as 100 days.

Doctors diagnosed chronic granulomatous disease in the 19-year-old when he was 3; Hooten started treatment at NIH at 9, when he qualified to participate in a study of the disease, which suppresses the immune system.

Last year, he underwent an experimental stem-cell bone marrow transplant, a procedure doctors hoped would permit his immune system to recharge. Stem cells are found inside the bone marrow and are used to fight infection. Now that the doctors have done a few more of the transplants, Hooten said he is optimistic that his second will be a success.

Meanwhile, he added, the inn has helped him to relax. "The inn is like a home for me," he said. "I can come here and not worry about anything else."