An assessment of the boundary conditions for pulsed laser ablation is presented in the case where a thermal sputtering mechanism is relevant at the surface of the molten pool formed by the effect of irradiation. This paper deals with, in particular, the evaporation and boiling mechanisms when superheating effects are allowed to occur. The non-equilibrium character of the process at fluences enabling superheating plays a critical role in the rise of a large temperature gradient and subsurface temperature maximum even in the presence of surface boiling by vapour bubble nucleation.