Abstract: An improved cast motor housing for medium to large motors is integrally formed with at least one conduit embedded in the housing for carrying a circulating heat removal fluid. The housing has a substantially cylindrical housing wall formed from a thermally conductive material. The fluid conduit is disposed within the housing wall intimate thermally-conductive contact with the wall material. The conduit may be formed of a sturdy, thermally conductive material. The conduit is arranged within the housing wall to extend along substantially the entire longitudinal and circumferential dimensions of the housing, and may be formed as a multi-turn helix. For larger motors, multiple conduits may be provided. The motor housing is formed by casting. A cylindrical casting core has a set of longitudinally-extending channels located at regular angular intervals along its circumference for supporting the conduit during the casting process.