Protection is given from thermal radiation by a reflecting layered material with micro-prisms (1) in an enclosed planar arrangement. Preferably the micro-prisms are retro-reflection prisms and allow total reflection at the boundary surface with the air for incident angles of radiation greater than the limiting angle for total reflection. The micro-prisms are preferably regular or irregular polyhedrons with three, four or more refracting surfaces, having at least one edge with a length of at least 1 mm.
