Are MOSFETs Sensitive to heat while soldering?
The difference in the structure of MOSFETs and BJT is that the former have a thin insulation layer. I don't know if this is easier damaged than the rest of the crystal when heating it. But I would most strongly advise you to get a temperature controlled soldering station. If you leave your iron unused for a minute the temperature will rise to levels components won't like.
Also, most likely a temp controlled station will have proper earthing which is even more important than temperature when soldering MOSFETs.