I'm soldering through the hole MOSFETs in to a PCB and I don't have a temperature controlled soldering iron. So will I need to heat sink the legs as I solder them to stop internal damage. I as this as bipolar transistors are damaged from heat.
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.
They shouldn't need any special precautions when soldering, in terms of heat, compared to BJTs. They will be a lot more sensitive to ESD, so it might be a good idea to take precautions against that.
The data sheet should give you the maximum soldering temperature and time.