The article discusses the importance of temperature management in rail systems, particularly focusing on energy consumption. The drive system of rail vehicles is highlighted as the primary energy consumer, necessitating efficient temperature control for electric trains operating without conventional energy supplies like overhead lines. The master thesis by Marcos Escamilla Sánchez at Fraunhofer IWU explores integrated thermal management in the DB class 490 train used in Hamburg's S-Bahn, praising its heat pump and waste heat recovery for optimal efficiency. This model, solely electric without an additional battery, boasts a high Coefficient of Performance year-round due to energy-efficient heating and air conditioning. The article emphasizes the potential benefits of integrated thermal management systems that connect drive systems, batteries, and power electronics through water circuits and heat pumps or chilled water air conditioning. While such systems may not significantly enhance efficiency in Hamburg, they prove advantageous in regions with consistent heating needs. Notably, vehicles with frequent stops and short distances, such as S-Bahn and U-Bahn systems, stand to gain the most from these systems by reducing weight and HVAC components. Sánchez, now at Alstom, asserts the significant impact such systems could have on energy balance and usability in battery-electric or hydrogen fuel cell trains requiring constant temperature regulation.