In summers I would bathe in cold water until I was blue and then some. My parents said that they used to be worried by it, but they realised I was totally OK. They would keep an eye on me, but if I was out of the bath, pool, or ocean for a couple of minutes I would be right back to warm.

All I remember as a kid is being unusually warm in almost any cold conditions. Even now the cold doesn't bother me much, certainly less than my peers.

I'm sure metabolism isn't everything there, but it probably helps.