MB3 24a: Placing a Cooked Item on Top of a Furnace on Shabbos (253:5) cont.

If something is already cooked and a non-Jew put it on the fire to heat it up it can be eaten bedieved. Having a non-Jew turn on your furnace on Shabbos. Asking a non-Jew to turn off the refridgerator light on Shabbos.