The paper presents comments on Baets' paper which reports an analysis of surface-emitting (SE) diode laser operation. Baets' thermal model of the SE laser appears to overvalue the active area temperature increase of the laser to a considerable extent. The paper attempts to illumine some errors which may exist in Baets' model. The thermal model of a Burrus-type light-emitting diode (B-LED), published recently, is adapted for this case, i.e. for the thermal analysis of the SE laser. In the B-LED model, a current-spreading effect, a two-dimensional heat spreading, a radiative transfer of the spontaneous energy as well as a temperature dependence of a thermal conductivity are taken into account whereas a Joule heating is neglected.