According to the "Code of Practice for Food Safety in Catering Services" issued by the US Food and Drug Administration, if a restaurant wants to sell cold dishes, it needs a special cold dish room in the kitchen. Cold dishes need a fixed temperature environment to avoid rapid decay, while hot dishes need to be roasted with fire, and the environment temperature is high. In order not to affect each other, the environment requires isolation. Secondly, cold dishes are mostly cooked food, and hot dishes are mostly cold dishes. For public health, raw and cooked food should be separated.