Is intercourse permissible during the period when the wife is prevented from washing her hair for 3 or 4 days, and how should ghusl be performed for prayer?

We have previously mentioned that if a woman is harmed by washing her head, she may wipe over it in ghusl from janabah instead of washing it, and once she recovers, she must wash it. This is a general ruling for anyone who fears harm from using water. In this case, there is no sin in intercourse, and for washing the hair of the head, it suffices to wipe over it, as we have explained. The intended harm is the occurrence of illness, or the delay of its recovery, or its worsening.