Abstract: A shield to protect the exposed surface of the casing of an evaporative cooler from the heat loading effects of the environment is comprised of thermal insulation means coupled to the exposed surface of the cooler casing and a weather protective covering coupled to both the insulative means and the casing of the cooler so as to protect the thermal insulation means from the environment and maintain the invention in place, covering and protecting the selected surface of the cooling casing to be protected. In the embodiment disclosed, the surface selected for protection is the top surface of an evaporative cooler and the insulation material may be comprised of a polyfoam insulative board configured to conform to the top surface of the cooler. A protective covering is set down over the insulative board and affixed mechanically to the casing to prevent the cover from being inadvertently dislodged. The invention is especially adapted to be retrofit to existing evaporative cooler installations.