Using circuit simulation software without incorporating electrothermal analysis to account for temperature effects and heat dissipation is a pretty big oversimplification impacting accuracy for many applications. Incorporating simple thermal resistance models and R-C network models are approaches that have been used. These typically involve either simplified methods or extensive calculation for more detailed reduced-order model creation.
There is now a more robust and straight forward way to create thermal data for electrothermal analysis in the form of thermal netlists in VHDL-AMS format, generated directly from 3D electronics thermal analysis using capabilities in the Simcenter Flotherm 2020.1 software release. You can also try out electrothermal analysis in a link below utilizing VHDL-AMS thermal netlists generated by Simcenter Flotherm.