heat sink on top of thermally resistive layer

does anybody now if it is possible to make a system like in the attached file, i.e. some structure with a heat source and a boundary with a heat sink, which is supposed to be a resistive layer at the same time.
I'm interested in building this thing without workarounds, meaning only layers and don't include any meshes.


a section through the system could look like:
physical -> comsol:
I) region with source -> reconstructed in detail
II) rather thin resistive layer -> using the feature of the 'thin resistive layer'
III) heat sink -> a boundary that is set to some temperature

if I do this in a naive way it's not allowed to combine II) and III)

any hint is appreciated, thanks in advance.
flo