Every year, two weeks before Christmas, Jeff Comment, CEO and chairman of Helzberg Diamonds, trades his business suit for a Santa suit and visits children's hospitals across the country.

The first year I visited children's hospitals as Santa Claus, I was scared to death. I knew how to run a retail company with 250 stores across the country, but this was wildly different. I was completely out of my element. I remember people asking me, "What are you going to say to a child who's dying?" I had no idea.

I went to Lutheran General Children's Hospital in Chicago for the first time, and someone told me that there was a boy with AIDS who had been asking to see Santa Claus. When I walked into his room, he got so excited. But he couldn't speak. His vocal cords were gone. His name was Jonathan, and he was 11 years old and weighed half what he should've weighed.

I sat on a stool next to his wheelchair and did what felt natural. I held his hand. I spent 10 minutes talking to him, telling him how much he meant to Santa. Everyone else--the nurse, his mom, my PR person--broke down and had to go out in the hall.

Before I left Jonathan's room, he did something extraordinary. He patted my hand. It was as if he was saying, "Keep doing what you're doing. You're right where you belong." He passed away a month later.

This is my eighth year doing the Santa tour. In all, I go to six or eight children's hospitals, spanning three or four cities, and visit about 2,000 kids a year. Some are burn victims, some are in intensive care, some are preemies whom the parents let me hold. I do the same thing with each child that I did with Jonathan: I give them my full attention.

Hospitals get many people volunteering to be Santa, but I've discovered that most aren't very good. I don't walk around making a lot of noise--"Ho, ho, ho!" and all that--and then leave 20 minutes later. A lot of these kids don't feel good. They need hope and comfort. They need a friend. I go room to room, giving each child a little bear that we make. I have a photographer with me. Everybody gets a picture with Santa.

The tour started after I got talked into playing Santa at our company Christmas party in 1995. We invited a charity that works with children who have been abused. When I asked what they wanted for Christmas, these kids said, "I want Mom to stop taking drugs," or "Santa, can I have a bed?" I wasn't expecting that, but I tried to be soothing. I told them that Santa loved them. I was wearing a mike, and everyone heard what I said. People told me it was one of the most moving parties we ever had.

Our marketing department suggested that I take my Santa act on the road the following Christmas, spending two weeks visiting children in cities where we have stores. It would be a way of giving back to communities that support our business. That first year, we went to Chicago; Minneapolis; Philadelphia; Dayton, Ohio; and Kansas City, Missouri.

Helzberg is a subsidiary of Berkshire Hathaway Inc. When my boss, Warren Buffett, learned about the Santa tour, he wondered how I could leave during our busiest season. I told him that if we're not ready by then, two weeks before Christmas, I haven't done my job. The merchandise is bought and in place; the people are hired and trained. The stores don't want me visiting; they're too busy. Since then, Warren has become one of the tour's biggest supporters.