A cylinder head assembly for an internal combustion engine has a housing (12) in which a plurality of elements (18, 44) are arranged. An optical duct (24) is formed in the housing (12) and is assigned to at least one of the elements (18). The optical duct (24) is assigned an infrared detector (28) that is designed to detect infrared radiation (30) from the at least one element (18) through the optical duct (24) to determine a temperature (T) of the at least one element (18).