Calculations of thermal fields during heating with pulsed and continuous laser radiation are presented. The obtained equations allow solving a wide range of technological problems. Calculations of laser treatment parameters that ensure heating to a given temperature at a given depth or ensure maximum hardening depth are illustrated. Based on calculations of thermal processes during heating with a laser beam scanning across the surface, the following has been determined: the minimum permissible scanning frequency to ensure a stable hardening depth along a hardening strip of a given width; the maximum heating temperature under the action of a heat source; the duration of the heat source with scanning, which ensures the cooling rate with hardening.