It's settled. I'm never going outside again.
As you step around to orient map to forest, you hear a metallic pop. You look down. The loose bail has disappeared from your binding. You lift your foot and your ski falls from your boot.
You twist on your flashlight, and its cold-weakened batteries throw a yellowish circle in the snow. It's right around here somewhere, you think, as you sift the snow through gloved fingers. Focused so intently on finding the bail, you hardly notice the frigid air pressing against your tired body and sweat-soaked clothes.
The exertion that warmed you on the way uphill now works against you: Your exercise-dilated capillaries carry the excess heat of your core to your skin, and your wet clothing dispels it rapidly into the night. The lack of insulating fat over your muscles allows the cold to creep that much closer to your warm blood.
Your temperature begins to plummet. Within 17 minutes it reaches the normal 98.6. Then it slips below.
It was a mistake, you realize, to come out on a night this cold. You should turn back. Fishing into the front pocket of your shell parka, you fumble out the map. You consulted it to get here; it should be able to guide you back to the warm car. It doesn't occur to you in your increasingly clouded and panicky mental state that you could simply follow your tracks down the way you came.