http://www.wikihow.com/Cook-Food-in-a-Hotel-Room

Lots of travelers, particularly those on business, find themselves stuck in hotels for weeks or months on end. The novelty of eating every meal at a restaurant soon wears off, and the traveller craves nothing more than a home cooked meal. However, in-room resources at many hotels appear to be incapable of facilitating cooking. This can be resolved in several innovative ways, which you should practice at home, and which you're really supposed to ask the hotel permission to do (and they'll probably say no).