Translate thermal contact into boundary condition, PDE Toolbox

Dear community,

I am modelling a thermal model via PDE Toolbox.

I have a complex geometry with multiple objects and I need to model what happens when they get in contact. I know the initial temperature of all the objects before they touch. I would like to see the temperature distribution in the main body during the contact. Apparently, I cannot model all the objects with the Toolbox as it only allows concentric or stacked couplings. Therefore, is there anyway I can translate the effect of the thermal contact into a non-constant boundary conditions to be imposed on the relevant faces of the main body?

Any help is much appreciated as I am running out of ideas.

Many thanks,

Giulia