National Cooler Day is celebrated on the Friday before Memorial Day in the United States, focusing on the appreciation of the cooler, an insulated box designed to keep food and drinks cool. The day highlights the cooler's significance, especially during the summer for picnics, vacations, and outdoor activities. Coolers utilize ice cubes or ice packs to maintain low temperatures and come in various sizes, including personal, disposable, reusable, and large wheeled versions. The modern cooler gained popularity in the 1950s, with significant contributions from companies like Coleman, which launched its first cooler in 1954. This invention has evolved from earlier methods of food storage, such as wooden barrels used by the Celts and the refrigerator patented by Thomas Moore in 1802. Today, coolers are essential for transporting perishable items and enjoying outdoor leisure activities.