Hmm dunno
If you're high enough to lose oxygen then you're definitely high enough to freeze
*EDIT* Consider a climber up mount everest. They can still breathe (albeit with difficulty) but the temperature is way below freezing.
(
Canker,
Mon 9 Jun 2003, 15:07,
archived)
Don't
they have oxy-ten masks though?
(
Mr Spleen Can do better. C-,
Mon 9 Jun 2003, 15:18,
archived)
Yeah
But only to aid their breathing because they're exerting a lot of energy.
They don't actually need it to survive.
What they do need though is lots of warm clothing :)
(
Canker,
Mon 9 Jun 2003, 15:22,
archived)