A method of treating a moving material web that is to be used in the fabrication of aseptic packages includes heating the material web prior to inserting the web into a heated bath of sterilizing agent so that when the web is inserted into the bath, the temperature of the web is at least equal to the temperature of the heated bath. The apparatus for carrying out that method includes a heating arrangement that is connected to a container that contains the heated bath of sterilizing agent. The container is positioned after the heating arrangement in the direction of movement of the material web. The heating arrangement includes a box and nozzles extending inwardly from the inner sides of the box. The nozzles are connected to a source of hot air and are adapted to blow hot air on both sides of the material web for heating the web.