Internal Parts of a Thermos Bottle


A thermos is used to keep hot drinks or foods hot and cold items cold. The thermos uses simple parts to accomplish the insulation process. Invented in 1892 by Sir James Dewar, the thermos has come a long way. Many homes have at least one.


Although the vacuum flask was invented in the late 19th century, it was not manufactured for commercial distribution until 1904.The trademarked name "Thermos" was the winning contest entry submitted by a German in the same year.


Air is used to insulate the contents. A glass vacuum bottle sits inside a steel or plastic shell.

Reflective Components

Silvering the vacuum bottle reflects heat that may escape or infiltrate the outer case.


An insulated stabilizer holds the vacuum bottle in place inside the thermos unit. This protects the glass from hitting the inside of the shell and breaking.

Fun Fact

Thermos was a trademarked name until 1962. A judge ruled that the word "thermos" was generic and that any company could use the name in lowercase letters to describe its thermal vacuum bottle flasks.