DENVER – On a freezing day, one driven and ambitious 8-year-old boy stayed outside to make sure his neighbors stayed warm.

Tristan Regini braved the cold Saturday by selling hot cocoa in his front yard to raise money for Children's Hospital.

"It's really cold," he said while shivering.

He credits doctors there for helping his best friend, Cade, fight cancer, so he wanted to pay them back.

"I was thinking of doing a lemonade stand, but I figured I could not do it in winter," Tristan said. "Children's Hospital saved his life, so now I'm trying to sponsor it even more."

At $1 a cup -- $2 with marshmallows – Tristan raised about $15 at his home on South Williams Street near Center Avenue in the Washington Park area.

Tristan's dad, Steve, said he was proud of his son, who came up with the idea all on his own.

" You know what? He's a warm-hearted little boy and it's just awesome to see him want to do it," he said. " It's ambition and it's also caring because of his buddy, so it's nice to see him do both, you know?"

At one point, Steve said he wasn't sure whether Tristan would actually go through with the sale, considering the temperature.

" I wasn't surprised, you know? That's pretty much Tristan. That's the way he is," he said.

But Tristan proved him wrong, and plans to donate the money on Sunday.

"If he had done this with me, he would've been very, very excited," he said.

(KUSA-TV © 2015 Multimedia Holdings Corporation)