Treatment of capillary fibers (I) without fixation comprises: applying reducing composition (A) (without ceramide) containing at least a reducing agent (when (A) does not contain aminothiols, thiols is less than 3 wt.% and when (A) contains at least an aminothiol, the thiol is less than 5 wt.%) on (I)； and elevating the temperature of (I) to 60[deg]C by means of an iron heating before/after optionally rinsing the fibers.
