Definition
A Dewar flask, also known as a vacuum flask or thermos, is a container designed to keep liquids hot or cold for extended periods. It consists of two flasks, one inside the other, separated by a vacuum. This vacuum significantly reduces heat transfer by conduction and convection. The flask's surfaces are often coated with a reflective material to minimize radiative heat transfer. Think of it as a high-tech cooler for your beverages, whether you need hot cocoa on a ski trip or ice-cold lemonade at the beach. It's like a personal temperature control system for your drinks! 🌡️