Originally Posted by
bijan
You are not moving on the chairlift and can use your warm hands to warm your ears, face, wherever else is cold. When cycling you are creating a 10 to 20 mph additional wind wherever you go... Look at what 20 mph of extra wind does to frostbite times:
Wind Chill Chart
Maybe you go faster going downhill when skiing but you don't do it for anywhere near 30 minutes at a time, let alone hours...
Indeed, and i've been skiing in very cold conditions also... the situation is not the same as a run rarely lasts long enough for the added wind-chill to really get you. When you get to the bottom there is plenty of time to warm hands and face... the issue with cycling is that the cold is often a non-stop head-wind for as long as you're on the bicycle. Your face has no time to catch up.
I should also add, that some people are less prone to frost-bit... i've heard(this may be wild rumour) Inuit and some northern europeans have on average slightly higher levels of subcutaneous fat on hands and face, theory being that the extra insulation helps them to stay out in bitter cold a bit longer.