Umm 'Attiyya said, We travelled with the Prophet, may Allah bless him and grant him peace, on seven raids. I travelled at the rear with the baggage. I prepared their food, and I treated the sick and the wounded." This hadith has been transmitted by Muslim.
Anas said, "The Prophet, may Allah bless him and grant him peace, once went on a raid, and he took Umm Saylam with him, and with her came some of the womenfolk of the Ansar. They used to take the drinking water around, and they used to treat the wounded." This hadith has been transmitted by Muslim.
Ahmad says that it is halal for a physician to examine a woman, even though they are not related, whenever it is necessary to do so, and including even the private parts. This was also the view of al-Maruzi in his Book of Ahadith, and of al-Athram, and of Isma'il. Similarly, it is halal for a woman to look at the private parts of a man in a case of necessity. This is what Harab stated in his collection of ahadith.
Al-Maruzi said, "Abu Abdullah's head was full of nits, so he asked a woman and she deloused him.
So it is clearly halal for a man to treat a woman to whom he is not related, and to see her private parts in cases of illness. And similarly it is halal for a woman to treat a man, and to see his private parts in a case of illness, and if there is no man or woman from his family at hand. Al-Maruzi said this in his Book of Ahadith.
In the same way, a witness is permitted to look at the face of a woman, and also whoever intends to conduct the marriage ceremony.
Again, if a man dies among women, or a woman dies among men, the women are permitted to wash the dead body of the man, and the men that of the woman. Thus there are two traditions, and in fact one complements the other.
Source: As-Suyuti's Medicine of the Prophet by Jalalu'd-Din Abd'ur-Rahman As-Suyuti , Ta-Ha Publishers Ltd, 1994, pp. 135-136.