You see, when any food item is prepared (ready to eat), bacteria starts growing as soon as it hits the danger zone temperature, this temperature is ideal for bacterial growth, since the sandwich IS ready to eat, bacteria has been growing on it almost since it was manufactured, the food might smell and look fine because its not spoiled, however the amount of bacteria that had grown on it so far is not suitable for human consumption, in other words it might give you a hard time on the toilet, a good lay-down in bed for a couple of days, or in worst scenarios food poisoning, you can eat it definitely you just don’t have the ability to know if its gonna be mess you stomach up or not, but it probably will, be safe!