A device for thermal separation between a conditioned environment and at least one external environment, which comprises a wall that has at least a first active layer-like region toward the conditioned environment, a second active layer-like region toward the external environment with respect to the first active layer-like region, a first insulating layer-like region, which is interposed between the active layer-like regions, a second insulating layer-like region, which is interposed between the second active layer-like region and the external environment. The active layer-like regions accommodate channels for the outflow of heat transfer fluids, which have, during the operation of the thermal separation device, temperatures that on average are different through the thickness of the wall.