What Is a Cooler Bag Used For: Top Uses, Benefits & Buying Guide

Every time you load a bag with ice and snacks for the beach, you’re relying on the humble cooler bag to keep perishables fresh and drinks chilled. But what exactly goes on inside that insulated pack? Cooler bags use layers of thermal insulation—foam, aluminum foil liners, and waterproof exteriors—to slow heat transfer, maintaining internal temperatures well below ambient for hours on end.