Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy and heat between physical systems. The ICFD solver offers the possibility to solve and study the behavior of temperature flow in fluids. Potential applications are numerous and include refrigeration, air conditioning, building heating, motor coolants, defrost or even heat transfer in the human body. Furthermore, the ICFD thermal solver is fully coupled with the thermal solver using a monolithic approach which allows to solve complex problems where both heated structures and flows are present and interact together.