The development of plasma scenarios compatible with metallic wall at JET requires both reliable and accurate surface temperature measurements and power load predictions, because of the reduction of the safety margins compared to the previous carbon wall. The code PFCFlux has been developed for heat flux calculations on those components, including shadowing effects. It has been implemented at JET, for the evaluation of the power deposition on the poloidal limiters (high and low field sides) and the divertor targets. In this paper, the concepts and methodology used are described. Two cases are then analysed, one of which is compared with infrared measurements. The global efficiency of the tool is discussed, as well as the need of "end-to-end" simulation composed of several simulations tools in order to correctly predict the measurement itself.