To preserve the ice as long as possible, people made sure to cool hot foods before putting them in the icebox.
All the refrigerator does is move heat, or energy, from one place to another. As the food inside the refrigerator loses its heat and gets colder.
What makes canning last longer than refrigeration? Learn more on this Moment of Science.
Back when most folks relied on an icebox to cool food, a block of ice was a precious commodity.If you put hot food in the icebox the ice might melt, and by the time the ice truck came through the neighborhood again all your food may have spoiled.