  We consider a scalar theory at finite temperature in the 2PI resummation
scheme, including phi^3 and phi^4 interactions. Already at the one loop level
in this scheme, we have to deal with a non local approximation. We carry out
the renormalization and obtain finite equations for the propagator. Within this
model we can explore the effect of non local contributions to the self-energy
in the evaluation of thermodynamic quantities.
