Many canned vegetables can be eaten right from the can (i.e. beans, beets). The canning process cooks and sterilizes the vegetables, making them safe to eat even without heating. There are some good summer dishes (three-bean salad or pickled beets on top of salads) where I would not reheat the canned veggie. Yes, you could also eat unheated canned vegetables for emergency purposes. Learn more about all forms—fresh, frozen, canned, dried, and 100% juice—of fruits and vegetables!