We previously developed a thermomechanical theory for the behavior of amorphous polymers near the glass transition based on the effective temperature nonequilibrium thermodynamic framework. The theory couples structural evolution (through the effective temperature) with plastic deformation to explain the inter-dependent effects of aging, mechanical rejuvenation, and plastic flow. The theory was able to predict experimental measurements for the effects of the annealing conditions and plastic deformation on DSC measurements of heat flow and mechanical measurement of yield strength and post-yield stress softening. In this work, we further extend the theory to describe the large deformation orientation hardening behavior amorphous polymers and the associated temperature-dependence and strain-rate dependence of the hardening modulus, the induced plastic anisotropy, and the Bauschinger effect. Orientation hardening is described by a backstress caused by inelastic long-range network interactions that modify the driving stress for plastic flow. We examined the effects of the temperature and structural evolution on the back stress and apply the model to describe the large deformation thermomechanical behavior of polycarbonate through the glass transition.