Dewar flask

A double-walled flask with a vacuum between the walls was constructed to help transport heat for low-temperature work. It became commercially known as thermos bottles for keeping drinks hot or cold.
 James Dewar England 1892 Dewar flask

A double-walled flask with a vacuum between the walls was constructed to help transport heat for low-temperature work. It became commercially known as thermos bottles for keeping drinks hot or cold.