As the subfreezing air struck your skin it tended to freeze. And frostbite is nothing but frozen skin. And when it freezes it forms a white patch. So men were constantly looking at each other's faces and hands to see if they could detect white, white patches. Otherwise gangrene would follow, so it was a constant threat.
Crevasses are a great danger in Antarctica in some areas.
Wherever there's land under ice and the ice has to flow over land it sometimes bends and cracks. And that's what crevasses are. There was submerged land just south of Byrd's base, and this formed big crevasses there. So the field parties, during the summer had to cross over these crevasses. I mean ice bridges over the crevasses and provided it's strong enough a dog team and a man can go over it.