Abstract: The dividing wall between a heat producing compartment of a helicopter, such as a compartment in which an engine or other power mechanism is located, and the pilot's cabin is made of a sheet of fiberglass that cannot withstand being subjected to an operating temperature that is in excess of about 200.degree. C. Accordingly, the hot side of the wall is lined with one or more liner blankets, each having a mineral fiber felt core, a metal foil front layer and a glass fiber fabric rear, supporting layer. These layers are quilted together and the result is provided with a binding about the periphery. The metal foil layer terminates somewhat short of the edge in order to make the margin more compressible. Each liner blanket is attached to the wall surface by a flexible adhesive. Where two or more of the blankets are used, they are placed so close together edge-to-edge that their respective margins are compressed, by abutment with one another preventing any unprotected gap.