An original method for the calculation of transient temperature distribution in a semi-transparent non-scattering condensed medium accounting for radiation and conduction is presented. This method was developed in order to detail the influence of interface properties on temperature distribution. Diffuse and specular reflections of the walls for three situations (contact of the vitreous boundaries with the walls on both sides, any contact on both sides and contact on one side only) are compared for a grey medium. Large differences are shown for the latter case. Concerning the situation with any contact between walls and the STCM, a comparison between vitreous interfaces governed by Fresnel laws and diffuse vitreous interfaces is given. Significant differences are pointed out. For a glass layer the differences cannot be neglected, but they are reduced because of high absorptivity in the IR range.