During the "Shabua She’Hal Bo Tisha B’av"-The week in which Tisha B’av falls, Sepharadim are permitted to take cold showers. There is a discussion whether this Halacha also applies to women. Rabbi Yaakov Castro (1525-1610, Egypt), in his Erech Lehem, ruled that women may bathe with hot water during this period. He argues that women were not included in the original Gezera (ordinance) since if forced to use cold water, they would most likely to forgo the discomfort and not bathe altogether. This would cause them to become unseemly in the eyes of their husbands and cause discord in marital harmony.
Hacham Ovadia was asked whether he subscribed to this opinion. He responded that if there would, in fact, be case in which not bathing would cause a problem in a marriage, he would agree to be lenient.
The prohibition of showering with hot water does not apply to women after birth, who have the status of sick people. A pregnant woman, even before her ninth month, may bathe regularly, if she experiences discomfort. In general bathing in hot water is permitted for a health related reason or for a Misva, such a Mikveh for a man or woman.
Of course, if possible, it would be preferable to adjust the temperature of the bath or Mikveh to lukewarm, where it is only warm enough to take the chill out of the water.
The Halacha also prohibits shaving and haircuts during the week leading up to Tisha B’av. There is no problem doing so during the Three Weeks or the Nine Days.
Healthy people, to whom the above leniencies do not apply, should be careful to observe these Halachot. The discomfort involved in not showering with hot water or not shaving for a few days, pales in comparison to our profound loss and mourning over the destruction of the Bet Hamikdash.
The prohibition of showering with hot water during the week leading up to Tisha B’av does not apply to women in cases where not bathing will cause marital problems, women after birth, pregnant women suffering discomfort, and any health or Misva related bathing.