What mishap occurs shortly after the man eats lunch and resumes his journey? Summarize his attempts to recover from this mistake. What other tragic misstep follows?

Shortly after stopping for lunch, in a seemingly safe, solid spot, the man falls through the snow and wets himself up to his shins. He curses his luck; starting a fire and drying his foot-gear will delay him at least an hour. He gathers brush and builds a fire, aware that his numb feet must not remain wet. The man begins to untie his icy moccasins, but before he can cut the frozen strings on them, clumps of snow from the spruce tree above fall down and snuff out the fire.