Thermos Bottle Day – February 26, 2025

History of Thermos Bottle Day

The history behind Thermos Bottle Day is unclear, but the story of the Thermos bottle itself is traceable to the early 20th Century. Though the word ‘thermos’ has become a household name used for any vacuum flask that stores either hot or cold liquid, Thermos is a brand name — the trademarked brand name of Thermos L.L.C.

In 1904, the Thermos flask was registered as a patent by German inventor Reinhold Burger, who later partnered with Albert Aschenbrenner and Gustav Robert Paalen. However, they were not the original inventors of vacuum flasks. Before this, a Scottish scientist known as James Dewar invented a vacuum flask for storing liquefied gas. It was not meant for everyday use. Although he was the first to create the vacuum flask, Burger was the first to register it as a trademark. Later, Dewar sued the Thermos company but sadly, lost the court case.

Thermos later faced similar problems as their trademark became a household name to the point that the word ‘thermos’ was now used to refer to similar products from other manufacturers, making it a ‘genericized trademark.’ Dictionaries even began including thermos as a word instead of a proper name. In 1962, a judge finally ruled that due to Thermos’ publicization of their product and lack of diligence protecting their trademark, thermos with a small ‘t’ could be used generically. However, the uppercase ‘Thermos’ solely belonged to the company.