The Thermos

A thermos is a special bottle that keeps your drinks at the right temperature. Hot cocoa stays hot, and cold water stays cold, for hours and hours. It is perfect for school, picnics, and trips.

How the Thermos Was Invented

The thermos was invented in 1892 by a Scottish scientist named James Dewar. He created a special bottle with two walls and a vacuum between them. The vacuum stops heat from moving in or out.

In 1904, a German company started selling Dewar's invention to the public. They held a contest to name it, and the winning name was Thermos, from a Greek word meaning hot. The name stuck.

How a Thermos Works

A thermos has an inner bottle and an outer bottle with empty space between them. This empty space is a vacuum, which means there is no air. Heat cannot travel through a vacuum very well.

The inside of the bottle is also coated with a shiny material that reflects heat back. Together, the vacuum and the shiny coating keep hot things hot and cold things cold. A good thermos can keep a drink warm for over 12 hours.

Fun Facts

• A thermos works because heat cannot travel through a vacuum.
• A good thermos can keep drinks hot or cold for over 12 hours.
• The word thermos comes from a Greek word meaning hot.

Did You Know?

Astronauts use thermos-like containers in space to keep their food and drinks at the right temperature.