We had a great discussion recently in the Outdoor Gear forum regarding "bugging out" and survival packing. Check it out.
http://www.bladeforums.com/forums/s...pse-trading-bin-instead-of-a-backpacking-pack
72 hours isn't very long at all; my longest solo backpacking trip was a week. Others backpack frequently for weeks or months at a time with only occasional resupply points. Forget about the Youtube "bug out bag" videos and look at what real backpackers have been carry day after day for the last fifty years.
(random backpacking picture found online)
72 hours = 9 meals. Sure you can eat nine consecutive no-cook meals, but it sucks. Hot food is nourishing, comforting, and uplifting. Add a stove, fuel, pan, and spoon.
That's also 3 nights. Tent and sleeping bag are critical in cooler temperatures.
Extra clothes are important, as you mentioned. I wear the same shorts and jacket for an entire trip, but fresh socks and underwear daily. Of course clothing needs are going to change seasonally. Extra shoes too.
This time of the year I wouldn't go overnight without long underwear, rain gear, and warm fleece in my pack. Hat and insulated gloves too.
Hygiene is important when traveling. Toothbrush, soap, etc.
Are you prepared to leave your home in case of a natural disaster, like the recent typhoon in the Philippines? The Red Cross has an excellent preparation list of necessary items here:
http://www.redcross.org/prepare/location/home-family/get-kit
I'd emphasize food, water, important papers like financial and insurance documents.
The single most important piece of advice I can give, get some experience using and carrying whatever gear you select. If you're comfortable and secure for a week on the trail when it's
not an emergency, you'll be more comfortable and secure when it
is. The best gear in the world isn't worth a crap if you don't know how to use it.
