Most are under a vent hood that provides a lot of air movement across them. Restaurants also have "make up" air-conditioning systems for the kitchen. They provide adequate cooling to compensate for the added heat load of the appliances. The doors have handles and are insulated to not get hot. So there's plenty of safety for them in a commercial kitchen.
No shit? Didn't know that. Particularly about the lack of insulation. That seems retarded, as if restaurants were immune from workers comp claims and suits.