Predicament: You're crossing a steep talus field when a rock shifts, folding your ankle like flimsy tent stake. You hobble over to a boulder as your foot begins to throb.
Lifeline: Loosen your boot, but don't remove it (swelling could make it hard to put back on). Test your ankle. If it can't bear weight, you feel severe stabbing pains, and you heard a "pop" when it twisted, you have a fracture or severed ligaments. Improvise a splint with a rolled sleeping pad, clothing, and straps, then evacuate to the nearest road. If the pain is manageable, you're probably facing a bad sprain (stretched or partially torn ligaments). Apply a water bladder or zip-top bag filled with cool water or snow as soon as possible to limit inflammation and speed healing. After 30 minutes, wrap your foot by threading an ACE bandage under your arch and around your ankle in a figure-8 pattern. Tie your boot as tight as you can stand it, and try walking. Offload gear to lighten your backpack, and make a crutch by wrapping a t-shirt over a pole. Your routine until you reach the nearest trailhead is RICE: rest, ice, compression, and elevation. Stop every hour to elevate and cool your ankle. Take ibuprofen to reduce pain and inflammation.