Heat Transfer - Interaction between two layers

[Fijy]

Hi,
I'm doing a project about heat transfer. I have two parallel layers which are move away from each other for a few mm. There is a surface heat flux on the first layer and, including boundary conditions on this layer, i get results: temperaure contours on it. Ok. Then, I want to make this results affect to the second layer. Which interactions or loads should I use? Or how I should mix them, to model my project. I think about making interaction of radiation in the inner surface of first layer. But I dont know how to make inner surface of second layer to get this radiation.

For better depict of my problem, its something like sunshield in telescope

http://www.jwst.nasa.gov/sunshield.html.

There is a sun as a source of heat flux and then are layers which are stopping heat flux.

Thanks,
Fijy