Many scientists contributed to the analysis of temperatures in grinding leading up to present-day understanding. This paper draws together important developments from various papers and aims to identify an improved general approach to thermal analysis with wide applicability including for conventional fine grinding, creep feed grinding, and high efficiency deep grinding. Complexity of the basic derivation is avoided since the resulting temperature model is based purely on heat balance. Challenges for future thermal analysis are indicated. Emphasis is placed on fundamental principles for improved accuracy and for convenience of application in process control.