122:12 We do not bathe during the Nine Days, not even in cold water. (One may wash his hands, face and feet – Mishnah Brurah 551:94.) If one has health reasons – such as a woman who has just given birth or one who is close to giving birth and washing is advisable for her, or a frail person whose doctor has told him to wash – they are allowed to wash even with hot water (except on Tisha b’Av itself – Shaar HaTziyon 551:94). A woman after her period may bathe and immerse in the usual manner. If she is going to the mikvah on the night after Tisha b’Av and she cannot bathe after, then she may wash the day before Tisha b’Av. Also, on the days when she wears white undergarments, she may wash a little in the usual way because she is not doing it for enjoyment.
122:13 If Rosh Chodesh Av falls on a Friday, one who is accustomed to bathe with hot water every Friday may also do so now, but on the Friday before Shabbos Chazon (i.e., the Shabbos before Tisha b’Av), one may not wash with hot water even if he is accustomed to doing so. Washing one’s face, hands and feet, however, is permitted (even with hot water – Mishnah Brurah 551:97). Similarly, one who is accustomed to washing his hair every Friday may do so, but not with soap or shampoo. (If Shabbos Chazon is the day before Tisha b’Av, then it is preferable for one to wash his hair before midday – Shaarei Teshuvah 551:37.) One who is accustomed to using the mikvah every Friday may do so but only in cold water. One who uses the mikvah only occasionally is not permitted to do so during the Nine Days.