An ice cooler box in its simplest definition is a portable device that is helpful for keeping perishable items or beverages fresh and cool for a long time. It is usually kept closed and is opened only when something is needed from inside of it. It is recommended to choose an ice cooler box of a light color to reflect most sunlight. It used well, it can preserve food at near-freezing point for anywhere from some hours to a couple of days. Ice tends to melt slowly and when it turns into water, it needs to be drained out, filling the cooler completely with new ice.
Keeping perishable items fresh and cold
A certain amount of heat energy is required to melt the ice. While this energy is absorbed by ice, the temperature remains almost same, however, it starts turning into water. An ice cooler box is meant to insulate, meaning the heat from the outside barely makes any difference. A big chunk of ice requires a lot of time and heat energy to melt. Even if the ice chunk starts melting, it keeps the food or beverages cold that are touching it.
Convection and conduction are the two ways that let the heat energy transmit and melt ice chunks. While convection means the flow of air, conduction refers to the heat, flowing directly thought the walls of ice cooler. If you keep the lid of the cooler closed, the warm air can't flow and melt the ice, meaning convection doesn't play a big role melting the ice. On the other hand, heat energy coming from the walls of the cooler melts more ice. That is why, it's highly recommended to avoid placing the cooler under the direct sunlight. Conduction takes place even if you place the cooler in the shaded area, but the process gets overall slower. Today, modern or expensive ice box coolers are made out of insulators to increase the ice retention property.