A cover plate is configured to be releasably connected to a concealed fire protection sprinkler to conceal the fire protection sprinkler. The cover plate includes a first layer of metal on a first side of the cover plate, the first side of the cover plate having the first layer of metal directly facing, in its entirety, the concealed fire protection sprinkler, and a second layer of metal on a second side of the cover plate, the second side being opposite to the first side. The second layer of metal is more resistant to corrosion than the first layer, and is bonded to the first layer. In addition, the first layer of metal facing the concealed fire protection sprinkler is more thermally conductive than is the second layer.