The book summarizes the current state of the most important thermal aspects of converter-fed electric machines. In addition to typical topics such as modeling, efficiency optimization, and resistance matching, it also covers the determination of time constants, temperature measurement, kT adjustment, demagnetization, and insulation aging. The focus is on practical application possibilities in real-time systems for modeling and efficiency optimization. The book is particularly suitable for engineers with industrial experience or as a textbook for students who wish to delve deeper into electric drives.