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WedFeb 26

Thermos Bottle Day – February 26, 2025

Thermos Bottle Day is observed every year on February 26. Since the company was founded in the early 1900s, the name Thermos has become synonymous with the vacuum flask. Now all products with similar uses come under the eponym ‘thermos.’ Thermos bottles are flasks specially designed to ensure that hot liquid stays hot and cold liquid remains cold. Thermos now produces a variety of items, such as food jars, mugs, tumblers, coolers, and lunch boxes. The Thermos consists of two compartments, one inside the other. There is a space from which air is partially evacuated, leaving a vacuum. This prevents cold or heat from escaping, which is why liquids can remain hot or cold for long periods.

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.

Thermos Bottle Day timeline

The Birth of an Inventor

Inventor Reinhold Burger is born in Germany.

Thermos is Founded

Thermos GmbH is founded by Reinhold Burger.

Massive Sales

Thermos sells over two million units of products.

Generic Thermos

A court rules that ‘thermos' can be used as a generic term.

Thermos Bottle Day FAQs

Do vacuum flasks expire?

Yes. Dropping or denting a vacuum flask may affect its ability to insulate beverages, especially if the flask is made of glass.

Can you put a thermos flask in the fridge?

Yes you can, though the liquid inside may take longer to become cool. However, if the inner flask is made of glass, it could break when the water freezes.

How long do liquids retain their temperature inside vacuum flasks?

It depends on the brand. Some vacuum flasks may keep liquids hot or cold for twenty-four hours or more. Others may retain temperatures for shorter periods.

Thermos Bottle Day Activities

  1. Buy a Thermos

    It might seem like a throwback to school days but take this holiday as a chance to buy yourself a nice thermos bottle. If you really don’t need one, gift a special someone a bottle.

  2. Carry a drink

    Whether you are going to school, work, or on an early morning stroll, put your favorite beverage in a thermos and carry it with you. Not only will it help you celebrate but it will keep you hydrated which is also important.

  3. Use the hashtag

    Create an educative post about the history of thermos bottles. Most people might be surprised at its colorful history. Don’t forget to use a hashtag like #thermosbottleday on your post.

5 Interesting Facts About Thermos

  1. ‘Thermos’ was picked from a contest

    The name ‘Thermos’, which was selected in a name-picking contest conducted by the owners, was submitted by a resident of Munich.

  2. Thermos has Greek origins

    The name ‘Thermos’ is derived from ‘Therme’, a Greek word that means hot.

  3. Thermos split into three companies

    In 1907, Thermos GmbH was sold to three independent companies, namely: The American Thermos Bottle Company, Thermos Limited in England, and the Canadian Thermos Bottle Co. Ltd.

  4. The Wright brothers used a Thermos

    The Wright Brothers took a Thermos bottle on a flight in their airplane.

  5. Count Zeppelin wasn’t left out

    Count Zeppelin once took the Thermos bottle up in his air balloon.

Why We Love Thermos Bottle Day

  1. We love innovation

    Think of a world without thermos bottles. We appreciate James Dewar's innovative idea. Because of bright minds like his, our world becomes easier every day.

  2. We love the convenience

    Without thermos bottles, we’d have to finish our drinks almost as soon as they’re poured to avoid lukewarm liquids. Thankfully, we never have to experience this, as cold stays cold and hot remains hot.

  3. We love entrepreneurism

    We love how Thermos has aggressively pursued its vision. Since 1904, the company has diversified into other products. They now produce various items, such as food jars, mugs, tumblers, and coolers.

Thermos Bottle Day dates

2025February 26Wednesday
2026February 26Thursday
2027February 26Friday
2028February 26Saturday
2029February 26Monday

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