Water (foil pouches plus a canteen to be carried)
Pocket water purifier
Water jug
Water purification tablets
Energy bars (look for those with the highest calorie count)
Rain poncho
Space blanket
First-aid basics (analgesic, adhesive bandages, moleskin, antibiotic cream, tweezers)
Extra socks, preferably wool
Comb
Lip balm
Toothbrush and toothpaste
Soap and washcloth
Hard candy or gum