In response to this thread, an idea slightly different: Pick your mutilation.
You are stuck in a position where you will either lose both legs just below the knee, or your dominant hand just below the elbow. The damage to whatever gets cut off will make the piece(s) totally unuseable and completely irreparable. You can get whatever prosthetics you want afterward. Which would you choose and why?
I would go for the feet. My primary reasons: 1) I can't write worth squat with my left hand. 2) I'm short, so I could add a couple of inches to the new legs.