if heat is transferred to an object , then the object will get hot
heat_production is energy_transfer. heat_exchanger is device. water_heater is heating_device. direct_object is object. space_heater is heating_device. space_heater is not heating_device. if_water is too_hot_will_burn. electric_heater is heating_device. heating_element is heating_device. heating_element is component.