another saturne question :)

Hi,
I'm trying to do a cfd study in order to find the main air fluxes around a small building.
I need to impose some temperatures to the boundary walls of my model.
I figured that it can be done adding passive scalars and assigning them as boundary conditions to the walls but how can I say to saturne that those scalars are temperature values?
And how does saturne consider them in the calculation?
If someone have some advice to give me about that i would be glad.
Thank you in advance