My stomach is very cold yet the rest of my body is warm why?

Your made that way: If you are referring to the outside of your body where your stomach is, i would say that reflects a non-serious alteration in the blood flow to the skin/tissue overlying your stomach. If you are referring to a sense of cold inside your stomach, that is likely a "misreading" on your part of the nerves in your stomach responsible for sending reports to your brain. In either case, this is not serious.