This paper presents a study of the hollow bulk electron temperature profiles measured in the low-temperature (2–15 eV) plasmas of the WEGA stellarator. For this the global power balance equation was solved for the bulk electrons. The observed hollow temperature profiles could be reproduced satisfactorily assuming that the bulk electrons are heated through energy transfer from fast electrons and that the parallel heat conduction in the scrape-off layer is determined by the potential drop in the sheath in the vicinity of the wall. These results imply that the cause of the hollow shape of bulk electron temperature profiles is the heating of them through collisions with fast electrons produced by the heating method.