The few items I carry in my pockets while backpacking are there for convenient access, not for my safety in case of emergency. As several others have said already, I do not stray far from my pack when I am hiking. As a rule it is within a few paces of where I am.

If I take any sort of hike away from my campsite I habitually bring any extra clothes, gear, food or water I think I might need. Because I hike solo, I never wander heedlessly, but always take care to know where I am and how to get back to safety at all times. This is mandatory and must never be ignored. It is far more important than any Altoids tin with a few bits of stuff in it.