The method and the device serve for the blow molding of containers. A preform of a thermoplastic material is first subjected to thermal conditioning in the region of a heating section along a transporting path. Subsequently, the preform is transformed into the container inside a blow mold by the effect of blowing pressure. The thermal conditioning of the preforms is carried out by a number of radiant heaters positioned one above the other. The radiant heaters are activated during production in accordance with a first heating profile and activated during standby mode in accordance with a second heating profile (50), which is different from the first heating profile.