Charles W. Bryant,

HOW STUFF WORKS, Anyone who has ever gotten a touch of food poisoning will tell you that spending the night hugging the toilet isn't a pleasant experience. Now imagine not having the relief that comes with a supply of fresh drinking water to rehydrate you or a comfy bed to regain your strength. Picture yourself alone and lost in the woods with no shelter. This is what's known as a worst-case scenario. Food-borne illness can leave you weak and unable to function. If you're stuck in a survival scenario, it can even kill you.

Sour Stomach

If you have some survival skills and you're able to hunt down or trap an animal for food, make sure you cook it all the way through and then some. There's no such thing as medium rare in this situation. Eating tainted or undercooked meat can mean you're chowing down on some serious bacteria like E. coli or salmonella -- not ideal when you're struggling to survive. You can also become ill by eating the wrong plant or insect.

Both Ends

Any kind of food-borne bacteria will lead to some serious diarrhea, nausea and vomiting. If things get worse, you might feel some abdominal cramping and fever setting in. In a survival scenario, food-borne disease becomes especially dangerous because you're losing fluids every time you pass food from either end, which leads to dehydration and weakness.

What to Avoid

It may be tempting, but even the freshest roadkill is something you should avoid at all costs. It doesn't matter if it's a potential meal; it could already be swimming with harmful bacteria. If you have no meat options and you're relying on insects and plants to provide your nourishment, avoid anything that's brightly colored, extremely pungent or has thorns or spikes. That's nature's way of saying, ""don't eat me."" Plants with a milky sap are also a no-no.

Insects 101

If insects are on the menu, pull off the legs, arms and head, and cook the body by boiling or roasting it for the best taste. You can eat most edible insects raw, but a nice rack of grasshopper skewers is sure to bring a smile to a survivalist's face. The legs and head won't offer much protein anyway, and it can help the flavor to get rid of them.