what is thermos

A thermos, also known as a vacuum flask, is an insulating storage vessel that is designed to keep its contents hotter or cooler than the surrounding environment for an extended period of time. It consists of a double-walled container with the air between the two walls removed to create a vacuum, which minimizes heat transfer by conduction, convection, and radiation. This design allows a thermos to retain the temperature of its contents, keeping hot liquids hot and cold liquids cold for several hours. The term "thermos" is often used as a genericized trademark for vacuum flasks, and it was first developed for consumer use by the company Thermos in 1904, which was the first to use vacuum insulation technology in consumer products