Abstract: Through the flanged trunnion of a heated roll for the treatment of a material web, more particularly a calender roll, a partial flow of the heat transfer fluid used for heating is diverted between the supply and return of the fluid so that the flanged trunnion is heated or cooled in its central portion. For influencing the radial expansion of the trunnion when subjected to heat and increasing the fluid flow heating or cooling the trunnion, the trunnion may comprise a central cavity sealing off the centerbore of the roll, the partial flow of the heat transfer fluid being directed through this central cavity.