I am doing PCB Level thermal simulation. I am keeping initial temperature as 35 deg C and Casing wall Temperature (Ambient Temperature) as 70 deg C. The system is a closed system with single board without any airflow. When the board Thermal simulation completes, I have observed that some of the ICs component is having case and junction temperature less than ambient temperature. it is coming around 65 deg C. Is it possible to have case and junction temperature of component less than the ambient temperature. Please help in resolving this ambiguity of thermal simulation.