Eden is right to suggest a Foreman Grill. It can be used to make all sorts of things.
Snowy's suggestion of an electric frying pan or a toaster over are great as well.
Something like this is pretty good as well. They are rated for indoor use. You can also go electric, but I prefer flame.
That said, if you are all set on not generating your own heat, you can always buy ready made meals from the deli counter. Most have rotisserie chickens that you can shred and mix into various types of salads and/or sandwiches.