Always temperature play an important role in tribology. but temperature changes with respect to contact load and type of lubricant. I think that healing process occur in some cases where the temperature goes down and so the friction then relaxation modulus will stop decreasing with respect to heat. I think the process will differ between boundary regime and elastohydrodynamics regime. Thus additives in lubricant play a significant role with respect to relaxation modulus.

Gabi Nehme et al did lots of research concerning your question but mainly in the boundary area, you can review these in major journals such as wear, tribology transaction, lubrication science...

hope I helped you.