In China, thermos flasks are an integral part of daily life, both inside and outside the home. The age-old custom of using them evolved from a chronic shortage of drinking water – still a persistent problem today. Consumers often have to boil water to make it drinkable. Thermoses make it possible to keep the water hot and use it for preparing tea all day.

This model from 1990 was produced by Deer Brand, China’s leading manufacturer of thermos flasks. Its large size makes it better suited for home use than travel. With its cork stopper and metal cup it can be tightly closed, and a handle makes it portable. The exterior wall is sheet metal; the interior consists of two glass flasks, one inside the other, attached at the neck and separated by a near-vacuum. This construction guarantees that the contents remain hot. Developed in 1892 by a Briton, James Dewar, who never patented the idea, this insulated storage vessel was marketed by a German company called Thermos in 1904. The product was a hit, and the brand became a household name.