Indium in Pb1-xSnxTe alloys forms a resonant energy level in the conduction or valence bands, depending on x. In this study we investigate temperature dependence of the In level from 80 to 400K, complementing our previous work at 80 K. Measurements of electrical resistivity, thermopower, Hall and transverse Nernst-Ettinghausen effect are used to assess carrier mobility, Fermi level and scattering coefficient. Measurements are performed on a set of p and n type Pb1-xSnxTe:In with 0 < x < 30 at% and In up to 3 at%. We show that with increasing temperature the Fermi level crosses into the gap. It had been suggested theoretically that hybridization of the In level with one band at the Fermi level could have had a positive effect on the thermoelectric properties of materials, but the present results illustrate the need for temperature-dependent modeling and experimentation.