In India, where I hail from, almost everything is served hot. When I had visited Canada, it took a person a while to understand when I told her, 'Please heat it.' (I know it was a blunder! :P )
I had to tell her that because she gave me a patty (or for that sake anything that is eaten either hot or at room temperature) that was of a room temperature.
My question is what is the commonest way to tell someone to 'heat' food so that an American or a Brit can understand it without any hassle. A few I can guess...
Please heat it (that failed miserably!)
Can I get it hot? (ambiguous)
Please serve hot (this seems ordering and harsh!)