2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45246We generalize the concept of dimensional reduction to operators involving fermion fields in high temperature field theories. It is found that the ultraviolet behavior of the running coupling constant plays a crucial role. The general concept is illustrated explicitly in the Gross-Neveu model.5 pages using world_sci.sty, which is appended to the file. Full postscript version available via anonymous ftp from risc0.ca.infn.it:/pub/private/lissia/infnca-th-94-17.ps (192.84.132.4) To appear in the Proceedings of the ``Workshop on Quantum Infrared Physics'', Paris, France, 6-10 June 1994High Energy Physics - PhenomenologyHigh Energy Physics - LatticeNuclear Theorytext