A cooler, cool box, portable ice chest, chilly bin (in New Zealand), or 'esky' (Australia) most commonly is an insulated box used to keep food or drink cool. Ice cubes are most commonly placed in it to help the things inside stay cool. Ice packs are sometimes used, as they either contain the melting water inside, or have a gel sealed inside that stays cold longer than plain ice (absorbing heat as it changes phase).
The portable ice chest was invented by Richard C. Laramy of Joliet, Illinois. On February 24, 1951, Laramy filed an application with the United States Patent Office for a portable ice chest (Serial No. 212,573). The patent (#2,663,157) was issued December 22, 1953.
The Coleman Company popularized the cooler, most popularly known as an "ice box" in the United States, with its initial offering of a galvanized cooler in 1954. Three years later, Coleman developed a process to make a plastic liner for coolers and jugs.
Coolers are often taken on picnics, and on vacation or holiday. Where summers are hot, they may also be used just for getting cold groceries home from the store, such as keeping ice cream from melting in a hot automobile. Even without adding ice, this can be helpful, particularly if the trip home will be lengthy.
They are usually made with interior and exterior shells of plastic, with a hard foam in between. They come in sizes from small personal ones to large family ones with wheels. Disposable ones are made solely from polystyrene foam (such as is a disposable coffee cup) about 2 cm or one inch thick. Most reusable ones have molded-in handles; a few have shoulder straps. The cooler has developed from just a means of keeping beverages cold into a mode of transportation with the Ride on Cooler.
In the United Kingdom the common name is a "cool-box". In the United States they are usually called a "cooler". In New Zealand they are generally called a "chilly bin", a generic trademark; the common Australian name of "Esky" is also a generic trademark.
Read more about Cooler: Thermoelectric Coolers