a thermal insulating blanket is disclosed for providing an insulating barrier across doorways , stairways , and other openings between a heated area and an unheated area . the thermal insulating blanket includes an inner layer of flexible and compressible insulating material and an outer layer of flexible material . means is provided for venting the air contained within the thermal insulating blanket to the ambient atmosphere when the blanket is compressed and restrained for compact storage . a resiliency inherent in the structure assures that the blanket returns to its pre - compressed state upon release of the restraints .