Dave Looman
Ansys Employee

Also, there is a negative temperature which is non-physical.  This issue appears to be the result of using too small a time-step relative to the 2nd order element size.  The smallest time-step that can be used is given in Section of the APDL Thermal Analysis Guide.  Workarounds are using a finer mesh, increasing the time step or using first order (Linear) elements.