A sheet is described. The sheet has at least one substrate and at least one coating, which reflects thermal radiation, on at least one surface of the substrate, wherein the coating on the substrate contains at least one adhesion layer, a functional layer containing at least one transparent, electrically conductive oxide, above the adhesion layer, a dielectric barrier layer, for regulating oxygen diffusion, above the functional layer, and an antireflection layer above the barrier layer, wherein the barrier layer has a thickness from 10 nm to 40 nm.