The invention relates to a temperature-controlled, rotating, rotational symmetric heat exchanger, particularly for the pressing mechanism, drying mechanism or smoothing mechanism of a machine for producing web-like products such as paper webs or plastic films. The heat exchanger can be temperature-controlled preferably with fluids or vaporous heat transfer media or with heating involving electrical means. The aim of the invention is to improve a heat exchanger of the aforementioned type as to achieve surface hardnesses of far greater than 400-450 HV and to minimize the chemical/mechanical corrosion even at heat transfer capacities >80 kW/m. To this end, the heat exchanger is plamatized.