have used it above 4000m with ice/snow all around and a glacier in the mountains (dunno the height). seemed to work fine. not too sure of the temperature though.
I think the first thing that would stop functioning is the battery.
Heard from a friend that if this were to happen, keep the camera under your jacket until the temperature rises back to the norm. temperature then use again.
okays, thanks for ur info..im going mountain climbing to at least 4000m above sea lvl.. temp there will be ard -15 to -20 degrees.. i need some advice on what to do b4 setting off..