Asalamalaykum wa rahmatullahi wa barakatu,
Regarding menstruation periods I would like to ask the following questions:
1.Are women allowed to have a bath whilst in haidh and nifaas? (I know that this will not make them pure from najasat but are they allowed to bathe because of hot weather and hygienic reasons?)
2.Are women allowed to do istinja using water whilst in period? (Women in our area refrain from using water saying this causes illnesses and is against the laws of haidh and nifaas; is this true?)
3:Are women allowed to drink cold water and ice-creams and other cold products during haidh and nifaas? (Again women in our area refrain strictly from this saying that it is not allowed both for medical and Islamic reasons?)
4:In our area women that are in haidh or nifaas still read salaah (in pretence-meaning that they don't recite anything but pretend that they are reading) in the presence of their fathers and other males using the excuse that they shouldn't know that their daughters, mothers or sisters are in this state. Is this allowed or not?
You have asked many questions but they all seem to originate from the notion that women become abnormal during menstrual cycle and they come under some sort of scrutiny from Shariah which is wrong.
There are only a few things that become forbidden for women during menstrual cycle period. All the things that you have mentioned in your question are perfectly permissible for menstruating women.
So, taking bath, eating ice cream, drink cold water etc... are all permissible for mestruating women.
And Allah knows best.
Mufti Ikram ul Haq
Fatwa Center of America