Translation of "dewar" into Spanish

A vacuum flask; a vessel which keeps its contents hotter or cooler than their environment without the need to modify the pressure, by interposing an evacuated region to provide thermal insulation between the contents and the environment. [..]

A glass or metal double-walled flask for holding a liquid without much loss or gain of heat; a vacuum bottle or thermos. Generally used for scientific purposes and in particular for cryogenic work. [..]