In addition to replacing the battery, the usual maintenance tasks of a laptop also includes cleaning the fan - or fans in the case of models with a dual fan design. This was not an easy task in the ThinkPad laptops of the P series until now. But this is changing with the new Lenovo ThinkPad P15 Gen 1.
https://www.notebookcheck.net/Lenovo-makes-cleaning-the-fans-easier-in-the-ThinkPad-P15-Gen-1.526273.0.html