It has been reported recently that domain wall mobility in Fe-based amorphous glass-coated microwire can be significantly different in the cases when magnetization reversal caused by domain wall motion results in different orientation of magnetization. This behaviour has been called unidirectional effect. The effect of temperature on domain wall velocity vs. axial magnetic field dependences was studied for glass-coated Fe77.5Si7.5B15 microwire samples with strong unidirectional effect. Unidirectional effect was observed for the whole temperature interval from 100 K up to room temperature. Analysis of the results obtained indicates that the model of a solid domain wall does not explain the observed v(H) dependences. It seems very probable that besides standard damping mechanisms also changes in structure (shape) of the domain wall as a function of velocity (magnetic field) should be considered. Understanding of this mechanism could also provide interpretation of unidirectional effect.