In this study, we formulate two-scale boundary value problems (BVPs) for thermo-mechanically coupled problems of heterogeneous solids in a variationally consistent manner. This formulation is based on an incremental variational framework[1], in which the instantaneous equilibrium state of the continuum body is determined by an inf–sup problem of a thermo-mechanically coupled rate potential. The corresponding stationary conditions result in a nonlinear transient heat conduction equation stemming from the gradient of the logarithmic temperature. For this reason, we originally introduce the logarithmic temperature as a state variable, rewriting the inf–sup problem for the heterogeneous solids. Owing to this setup, the formulation of two-scale BVPs is straightforward, and the resulting governing equations on both scales are variationally consistent. To consider the transient changes in the microscopic temperature field, we assume that the heterogeneous solids are constructed from periodic alignments of finite–sized unit cells. In this regard, we follow by the formulation of a method of transient two-scale analysis, such as the introduction of an approximative two-scale decomposition[2]. We also originally construct an FE2-type semi-implicit numerical scheme by extending the tangential homogenization technique[3] to a thermo-mechanically coupled problem. The validity and performance of our proposal are verified by solving several numerical examples, such as heat conduction, thermo-elastic, viscoplastic problems, as well as studying the effect of unit cell size on multiscale coupled behaviors.