Given the high technological maturity of internal combustion engines (ICEs) and the much higher energy content of hydrogen storage systems in vehicles compared to batteries, there is an increasing interest in ICEs powered by hydrogen as a CO2-free solution for on- and off-road vehicles as well as construction equipment. Efforts are therefore being made to replace Diesel and natural gas engines with hydrogen ICEs with at least the same power density and efficiency. The occurrence of uncontrolled combustion phenomena (pre-ignition and knocking) is the limiting factor for the performance of hydrogen engines. In this context, the homogeneity of the air/fuel mixture, the avoidance of hot zones in the combustion chamber, the appropriate layout of the ignition system and the lubrication oil formulation are decisive factors for avoiding combustion anomalies. With this in mind, FEV has applied its patented arterial cooling system to a heavy-duty cylinder head for a hydrogen ICE with direct injection (DI) to ensure efficient and precise cooling of the combustion chamber. The arterial cooling system also enables an appropriate positioning of the injector and the design of the intake ports to produce the necessary charge motion. This work details the layout and performance of the heavy-duty cylinder head with arterial cooling in comparison to a conventional cylinder head design. 3D CFD mixture formation simulations have been performed with both designs to compare the charge homogeneity inside the combustion chamber. 3D CFD cooling fluid simulations highlight the differences in the cooling performance of both concepts. Furthermore, thermomechanical simulations for both concepts are presented to compare the arterial cooling with the conventional solution in terms of structural temperatures and durability. All these simulation results are compared with test bench results from the single cylinder testing of the different cylinder head configurations. .