Assalaamu alaykum wa rahmatullaahi wa barakaatuhu. I reside in a country where when hospitals are visited for treatment, there are many non-Muslim nurses and staff there. And among the Muslims there are those from innovated sects at times, and they do not act rightly, and its risky even to get treated by them at times, and Allaah, The Exalted, knows best. It is true that a Muslim woman should not undress herself at all, but for medical treatment it is permitted. Now, if the nurse provided is a non-Muslim female who cares well and the Muslim one that they may provide if a Muslim nurse is asked for is an innovator, then what is preferred in my situation? Political unrest is really problematic, and the sectarian conflict is the issue these days. Regarding medical treatment, it says that if it is a necessity, then one can undress, but there are certain tests needed to be done to diagnose the illness, hence, do they fall in the category of necessity? Examples of these are ECG or chest x-rays, and so on? And what is the ‘awrah (what should be covered of the body) of a Muslim woman that she should cover in front of another Muslim woman and that she is should cover in front of a non-Muslim woman? May Allaah reward you.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger. 

The jurists established that the Muslim woman [doctor/nurse] comes in priority in treating another Muslim woman and that a non-Muslim woman should not treat a Muslim woman while a female Muslim doctor/nurse is available.

With regard to women from innovated sects, they are of two kinds:

(a) If her innovation takes her out of the fold of Islam, then her ruling is like the non-Muslim woman. If there is no other [Muslim] woman to treat her, then the trustworthy and more experienced one amongst the two comes in priority.

(b) If her innovation does not take her out of the fold of Islam, then, in principle, she comes in priority over a non-Muslim woman, except if there is a preponderant benefit, such as experience and so on.

On the other hand, it is not permissible for a woman to allow a female nurse to see from her body what she is not permitted to see except for a necessity or a dire need. To learn about the ‘awrah (body parts that should be concealed as per the sharee'ah) of a woman in front of another Muslim woman and in front of a non-Muslim woman, please refer to fataawa 92295 and 82459.

The ruling differs depending on what is meant to be exposed from the woman's body [i.e. what has to be examined from her body] when treating her; it is not permissible to expose some part(s) of her body except in case of dire necessity, and some parts should only be exposed to the extent that is needed.

Al-'Izz Ibn Abdus-Salaam said in Qawaa’id Al-Ahkaam:

“It is an obligation to cover one's ‘awrah, and this is among the best acts of chivalry, and it is among the most beautiful habits, particularly in regard to non-mahram (marriageable) women, but it is permissible to reveal it for a necessity and a dire need. The dire need: such as each spouse looking at the other ... and the doctors looking at the woman for the need of treatment.

The necessities: such as the treatment of surgeries, and it is a condition that there is a dire necessity in order to look at the private parts as this is obscene; while this is not a condition in looking at other parts of the 'awrah [i.e. other than the private parts]

Also, the necessity or dire need that should exist in looking at the ‘awrah of women is not the same as that that should exist in looking at the ‘awrah of men; because by looking at the ‘awrah of women it is feared that one would be tempted; also, looking at the thighs, which are closer to the knees, is not the same as looking at the private parts.” [Abridged]

Allaah knows best.