  Constitutive equations are proposed for the relaxation of a glassy material
in contact with a thermal reservoir. The dynamics of a single state variable,
identified as an effective temperature accounts for the emergence of glassy
behavior at low bath temperature. Memory effect in cooling/reheating
experiments are discussed along with several aspects of the response to shear:
aging of the response to step strains, response to oscillatory forcing, and
steady rheology.
