In Sweden and Finland the resort hire shops normally have a big bucket of helmets for people to borrow for free or for a small fee. The warmth aspect is a big bonus but after a couple of near misses with trees trying to keep up with my kids I can see the real value as well.
OP be aware that sizes are a total hit and miss affair between the manufacturers. I've got a Xen for the bike but hate the fit of the Giro ski helmets I've tried.

