It was bedtime for Rudy Hummel. He pulled on three pairs of pants and four shirts. He slipped into a pair of boots. He walked out into the starry December night and headed for his snow house.

It was bedtime for Rudy Hummel. He pulled on three pairs of pants and four shirts. He slipped into a pair of boots. He walked out into the starry December night and headed for his snow house.

The temperature was 8 degrees.

For Hummel, 17, this would be his 193rd night in a row sleeping outdoors. He started June 7, sleeping on an elevated platform in a copse of balsam fir in his backyard.

"Originally, it was just going to be for the summer," he said. "I thought it would be cool to spend the whole summer sleeping outside."

An outdoorsy kid in an outdoorsy family, he enjoyed dropping off to sleep listening to the owls. He liked waking up to the sound of birdsong and to shafts of sunlight slanting through the balsam boughs. September came, and he wasn't ready to come inside.

"I thought, 'I need something more fun,' " he told the Duluth News Tribune.

So, he decided to shoot for a full year of sleeping outdoors. When winter came on, he built the snow house. He piled up a mountain of snow, let it set up and then hollowed it out. He finished building his snow house on Dec. 10 and has been sleeping there every night since.

"I've always liked setting goals and making them, challenging myself," said Hummel, who's working toward his Eagle Scout rank.

"Another part is, I really like sunrises."

At the tunnel entrance to his backyard snow house, Hummel wriggled through the entrance and crawled atop his pile of bedding on a snow shelf. The place was homey, if tight. A string of blue Christmas lights was strung across the roof. A tiny Christmas tree — with lights— sat in a corner of the white house. A small rug covered part of the snow floor.

Hummel punched a remote switch, and all of the lights came on. The blue light gave the distinct impression of cold storage, but Hummel knew he would be toasty again that night. Already, he had weathered nights as cold as 17 below zero with no problem. He had his sleeping system down cold.

Beneath him, atop his snow shelf, lay two foam pads, 3 inches of straw, a Therma-Rest foam pad, a thick foam pad and an empty sleeping bag. He would sleep in four sleeping bags topped by a quilt and a blanket.

The snow house smelled like straw, which littered the white floor. In this holiday season, Hummel seemed to be occupying his own Nativity scene.

Hummel loves the snow house, which he learned to build as a Boy Scout here in Duluth. Earlier, when his family lived in Alaska, he had winter camped in snow shelters as part of a Boy Scout winter program. The snow house is a clear upgrade from his platform in the trees, he said, which was getting a little uncomfortable as winter came on.

"I was sick of the tree house," Hummel said. "When it was windy, the snow would blow in. I'd wake up with an inch of snow on me. My quilt would be encrusted with ice."

Even in summer, the tree platform had its challenges. Wind rattled the tarp over his head. Thunderstorms kept Hummel awake some nights.

The snow house, with its foot-thick walls, deadens all sound except that of passing planes, Hummel said. The first night he went inside, he kept hearing a soft tapping that he couldn't figure out. Finally, he identified it.

"That is me blinking," he told himself. "I could hear myself blink."

His parents, Mark Hummel and Gail Johnejack, are completely supportive of their son's outside sleeping quest. They are a camping family. They know cold and how to dress for it. They made sure the snow house was constructed safely.

Not that Johnejack hasn't worried a night or two, especially as winter came on. But the family has a photo in a scrapbook from a family camping trip to South Dakota's Badlands. The photo shows Rudy Hummel in a tent, holding a book about rattlesnakes. That was the first night he slept alone in his own tent. He was 5.

"It was just a natural progression that he'd want to do this," Johnejack said.

Most of Hummel's friends don't understand his desire to sleep outside for a year.

"They think I'm crazy," he said. "They think it's pointless and stupid."

He shrugs that off, moves on.

His sister, Heidi, 14, agrees with his friends.

"He's crazy," she said. "I think what he's doing is great, but I like my bed too much."

She has promised, however, to spend at least one night in the snow house with him.

Hummel, with more than six months of outside sleeping behind him, is fully confident he'll reach his goal.

"No matter how cold it is, if I'm wearing enough, I'll be fine," he said.

Lately, he has been thinking about using his sleeping-outside experience to raise money for charity, getting people to pledge so much per night for a good cause. He hasn't quite nailed that down yet, but he's working on it.

Now, it was time for Hummel to sign off. He pulled a stocking cap down until it covered his nose. He slithered into his nest. He flicked off his Christmas lights.

Outside, a full moon shone down on the snow. Holiday lights glittered in the neighborhood.

In the blackness inside his house of snow, Hummel settled in for another silent night.