I've not verified this but I have heard that children through teens can handle cold temps in ways that adults cannot. Something changes physiologically post-puberty, maybe. Someone can fact check me on this.
Anecdote: During winters in my early high school years I would often wear shorts and flip flops to school. I waited outside my house for the bus on numerous occassions, and our neighbors thought my parents were nuts for letting me do that. It was cold, but not awful.
I would struggle more now if I tried that.