To me the most dangerous injury is the one that I am untrained or ill equipped to handle. An ankle sprain can lead to a life-threatening situation if it eliminates my mobility preventing me from obtaining life-sustaining necessities. A severe burn, which might not be immediately life threatening, if left untreated can lead to dehydration, infection or reduce/eliminate ones' mobility, which in few days result in death. I think you need to look at the bigger picture; there is not any one thing that is the most dangerous. Read, study, ask questions (there are no dumb questions only those left unasked) train and equip yourself, this will allow you to analyze any situation quickly, take action, and make them less threatening. Pete