A heat-insulating device for use in a processing line for a metal strip to be transported along a strip conveying direction, preferably for use in a rolling mill, wherein the heat-insulating device has: at least one heat-insulating carriage which has a heat-insulating hood which, in order to reduce temperature losses, can be moved over the metal strip; and a transport, which has a drive for moving the heat-insulating carriage and is configured in such a way that the heat-insulating carriage can be moved out of the processing line and into the latter horizontally, preferably along a straight line.