The thermal performance of different modules of plasma-facing components (PFCs) is analyzed for the DEMO reactor conditions in steady-state operation with the inclusion of the transient edge-localized modes (ELMs) for mitigated and unmitigated cases. As an example, the effect of these loads is considered for the tungsten (W) alloy mono-block design with a Cu OFHC/EUROFER water coolant tube first proposed in the framework of the Power Plant Physics and Technology (PPP&T) divertor study. A variant of this design with a EUROFER tube connected to the W block with a diamond/copper composite (DCC) used in the diagnostic windows is also analyzed. A design goal is to find the optimal thicknesses of material layers that allow one to keep the maximum temperatures within the allowable design limits under ITER water cooling conditions. Heat transfer and armor erosion due to the plasma impact has been modeled by using the MEMOS code.