Any dried, air-cured, or fermented meat will keep longer than most American grocery store shoppers would imagine. That stuff was invented way before refrigerators for a reason. Pretty much anything in a casing that is not obviously raw I guess would be a rule of thumb. Dried stuff is usually easy to distinguish from cooked but moist stuff. Stick with harder, drier stuff in the hot summer--same with cheeses--just so they don't melt and ooze. When the temps drop, you can bring almost anything if it's just a weekend. Boars Head makes some great products that grocery stores here carry (GA). If you have a Trader Joe's near you, they carry Columbus brand which is a real treat. Don't worry about some white mold on the outside--that's normal and you'll see some really good stuff sold that way--just wipe it off or eat it. Peel the casings if you want--some are almost invisibly thin and you just eat, others are like a tire--you'll know the difference.
Unless I'm carrying a whole sausage and a knife, I often get the grocery deli to slice whatever I want, separating meal-sized portions for me with layers of plastic film as they stack it. I can slap them on bread or tortillas or just eat them plain without getting my hands greasy (or the food dirty).
I know this is pretty scary sounding, but lately I have been buying pre-sliced salami and pepperoni at the local dollar store. They come in individual packs (Starkist tuna packs too). Not high quality meats, of course, but perfect for trail lunches since the sealed packaging helps reduce odors. Get used to eating this way and you can leave your stove and fuel at home. Chocolate covered espresso beans can replace coffee if you are a caffeine addict.