Packets of EmergenC , like alka Seltzer , good to have in the field , as your diet isnt all that great to begin with , and might keep you from getting sick in the first place . NUUN rehydration tabs , for those that live in a warm climate and sweat , they work ! I went through a tube a day in death valley , I found lemon lime to be the least offensive flavor , none are sweet , which is the way you want it to be . Energy gel packets , some are better than others , but helps give a quick boost when you need to keep going , but feel yourself dragging a$$ . You might be able to substitute that for the military caffeinated chewing gum , depending on how you react to caffeine . After the morning cup of coffee , it doesnt do much for me . Small bottle of Iodine , works on many things . Easy to carry . Ginger powder ………in case you eat something that doesnt agree with you . Powders and tabs in general are good to have , dont weigh anything and dont take up hardly any space . I make my own “envelopes ” , by cutting small strips of paper , taping the edges , pouring whatever powder in , then taping the top .