A cooler, portable ice chest, ice box, cool box, chilly bin (in New Zealand), or esky (Australia) is an insulated box used to keep food or drink cool. Ice cubes are most commonly placed in it to help the contents 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). 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. Some coolers have built-in cupholders in the lid. 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. A thermal bag, cooler bag or cool bag is very similar in concept, but typically smaller and not rigid. History The original inventor of the cooler is unknown, with versions becoming available in various parts of the world throughout the 1950s. The portable ice chest was patented in the USA 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. In 1952, the portable Esky Auto Box was released in Australia by the Sydney refrigeration company Malley’s. Made from steel and finished in baked enamel and chrome, with cork sheeting for insulation, the Esky became the first mass produced cooler on the market. The brand found huge success and by 1960, 500,000 Australian households owned one (in a country of approximately 3 million households at the time). The Coleman Company popularized the cooler within the USA with its initial offering of a galvanized cooler in 1954. Three years later,