Plastic preforms are transported during their heating along a predetermined transport path and rotated with respect to their longitudinal axis during transport along a first transport path section to achieve uniform heating of the plastic preforms in the circumferential direction. The plastic preforms remain at least in sections in a predetermined first rotational position with respect to their longitudinal axis during their transport along a second transport path section so that first predetermined circumferential sections of the plastic preforms are heated differently from second predetermined circumferential portions of the plastic preforms. The plastic preforms remain at least in sections in a predetermined second rotational position with respect to their longitudinal axis during their transport along the second transport path section, the first and the second rotational position differing from one another by a predetermined differential angle.