  In perturbation theory the infrared structure of the electroweak interactions
produces large corrections proportional to double logarithms log^2 (s/m^2),
similar to Sudakov logarithms in QED, when the scale s is much larger than the
typical mass m of the particles running in the loops. These energy growing
corrections can be particularly relevant for the planned Next Linear Colliders.
We study these effects in the Standard Model for the process e+ e^->f fbar and
we compare them with similar corrections coming from SUSY loops.
