Large heavy duty milling and boring machines are commonly used in demanding sectors such as oil&gas, wind energy, aeronautics, etc. Heavy duty operations lead to high heat dissipation within the machine, and this combines with the ever increasing accuracy requirements in these high added value applications. Therefore, machine builders need to implement smart thermal management strategies to be able to meet customer demands. The general challenge is described here, and a thermal error compensation system developed for large milling and boring machines is presented next. Finally, experimental results are shown to demonstrate the effectiveness of the system.