Using leftovers has been the cause of many outbreaks of food poisoning becauseof improper cooling and reheating (of “hot” leftovers). Leftovers that areintended to be served hot pass through the danger zone twice (during the initialcooling of the hot food and when reheating). Those leftovers intended to beserved without reheating, or as an ingredient in other foods (e.g., sandwich filler),go through the danger zone during cooling and then, when being prepared andportioned, often stay in the danger zone for another long period. The time in thedanger zone adds up unless the food is quickly cooled and then quickly reheated(if being served hot), or kept cold until serving (if not being served hot).