Good evening all: I am translating an inspection done in a kitchen and there is a reference to "timbre frío". I have looked for a definition for "timbre frío" everywhere but have not been able to find anything. I wonder if it is hospitality jargon? Anyway the context is: En el momento de la visita uno de los timbres fríos se encontraba apagado, había alimentos en su interior. Doesn't sound good for the establishment whatever a "timbre frío" is. I would appreciate a definition/synonym or translation. Please no wise cracks about attempting the translation for myself first - I can't do that if I don't know what I'm translating!