Abstract: A conduit for the transport of fluid at a temperature different from the temperature of the immediately surrounding ambient atmosphere may be quickly and efficiently protected against thermal transport by an insulating device comprising an elongating sheet of flexible heat insulating material having a length terminated by a top edge and a bottom edge, having a width slightly greater than the equitorial dimension of the fluid conduit and terminated by a first side edge and a second side edge and having an interior conduit-facing side and an exterior side, and means for releasably securing the elongated sheet about the fluid conduit.