a cooking technique called flash boiling uses a small amount of water to quicken the process of boiling. for example, this technique can be used to melt a slice of cheese onto a hamburger patty. the cheese slice is placed on top of the meat on a hot surface such as a frying pan, and a small quantity of cold water is thrown onto the surface near the patty. a vessel (such as a pot or frying-pan cover) is then used to quickly seal the steam-flash reaction, dispersing much of the steamed water on the cheese and patty. this results in a large release of heat, transferred via vaporized water condensing back into a liquid (a principle also used in refrigerator and freezer production).