Well, frankly, this hits at the very root of survival. In such a disaster scenario, finding yourself alone and poorly equipped in an unfamiliar environment, all bets are off and you do what you have to do to keep yourself upright and breathing in and out. Otherwise, you may not get back to your family and friends.
No one else is likely to do this for you.

I suppose fundamental to this is trying to avoid putting yourself in harm's way in the first place. For starters, I wouldn't advise going hiking anywhere near North Korea, Afghanistan, or Iran. Or, as a teenager, going on a single-handed around-the-world sail. Apparently some people don't see the common sense in this, and hopefully will have made appropriate preparations to deal with the consequences.