The Thermal/Environmental Control System (T/ECS) of the Columbus Attached Pressurised Module (APM) requires extensive modelling to assess the overall system performance and interfaces compatibility, and to verify the design capability of the specific functions of the Thermal Control System (TCS) and Environmental Control and Life Support System (ECLSS).The thermal/environmental design of APM relies on TCS active (Water Loop) and passive thermal control functions, while ECLSS provides racks air cooling and cabin temperature and humidity control.The selected modelling approach uses an Integrated Overall Thermal Mathematical Model together with a set of additional TMM's for detailed tasks. The Overall TMM (up to 900 nodes, written in ESATAN to exploit its special modularity features) allows the element thermal balance verification and the provision of the sink and interface temperatures for the equipment thermal design. Other available models are the Simplified Active TMM (up to 150 nodes, written in ESACAP and dedicated to parametric and trade-off analyses) and the Local Thermo-Hydraulic Models (up to 250 nodes each, written in ESATAN-FHTS and dedicated to hydraulic performance verification).Specific module enclosures, e.g. racks and subfloor, require dedicated modelling, for which the use of special-purpose thermofluid-dynamic software, like PHOENIX, is foreseen. Moreover, each Subsystem provides its own detailed thermal/hydraulic model. An overview of the Columbus APM thermal models is provided, discussing modelling and software characteristics.