if the can is truely tin and not aluminum or steel then I wouldn't cook in it. Tin contains Zinc and Mercury both of which will come out in the cooking. The plastic lining might prevent this as it does when the food is initially packed in the can. Most canning is done at around boiling temp if not slightly higher to ensure that the food is sterile when packaged. This is fine until something scratches the plastic lining. If you have a can that is un-lined and used to contain food then it is probably not tin since that would have been very un -healthy in the first place. I would think that, unless you are on a severely constrained budget that the cost of a stainless container would be worth the price. You might check into the picnic boxes that truxbx found. or the simple coleman cook set which is made from nesting aluminum boxes. If you want to put your cook pot in your stove then you might check out these cooksets

or this stove and cookset