We present a theoretical model and experimental measurements of the temperature field produced by the multiple scattering of thermal waves between two close subsurface cylinders and the material surface. The thermal waves are excited at the surface of an opaque material by an extended modulated optical beam. The cylinders are taken as thermal insulating holes and the model is run for a variety of modulation frequencies, thermal properties of the sample, and geometric properties of the cylinders (sizes, depths, mutual separation). The photothermal signal obtained using an infrared radiometry technique on calibrated samples validate our model predictions. The model is used to address the question of the spatial resolving power in photothermal wave experiments and introduce a novel resolution criterion.