Food Poisoning is most likely caused by unsanitary conditions and /or poor or inadequate refrigeration. Bacteria can grow very quickly out in the desert, woods, wherever.
Some of the rules my wife and I follow if we are out:
1. DON'T let uncooked meat float in ice water even if wrapped in cellophane. The water will quickly become a cold bacteria soup. Drain the cooler and refill with fresh ice whenever possible.
2. WASH YOUR HANDS...with soap and hot water. We keep a Jet Boil in the truck for heating water so we can wash our hands before digging around in the cooler for munchies. Also wash any utensils, plates etc...even a scalding water rinse is better than nothing. Or use throw away.
3. Rubber gloves. Cheap, disposable and sold in boxes of 100.
4. Learn to like non refrigerated foods, jerky, trail mix, granola, protein bars, energy bars, freeze dried stuff. Not always gourmet, but it will get you by for a few days.
5. Get a Garmin InReach (or similar) two way satelite communicator. If you do get sick, injured, snake bit etc. You can get hold of someone to provide emergency assistance. Cheap protection considering it could help save your life someday. Pray you never need to use it...
Good Luck!