Praise be to Allah.
It is not permissible for those in charge of hospitals to put a male nurse and a female nurse on duty overnight on their own to keep a watch on the patients. This is wrong and is a great evil, and it is a call to evil actions. If this man is alone with this woman in one place, they are not safe from the possibility that the Shaytaan may make immoral actions and the things that lead to such actions attractive to them. It was reported in a saheeh hadeeth that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “No man is alone with a (non-mahram) woman but the Shaytaan is the third one present.” So this work is not permissible and you have to leave it, because it may lead to that which Allaah has forbidden. Allaah will compensate you with something better if you leave it for the sake of Allaah. Allaah says (interpretation of the meaning):
“And whosoever fears Allaah and keeps his duty to Him, He will make a way for him to get out (from every difficulty).
And He will provide him from (sources) he never could imagine” [al-Talaaq 65:2-3]
“and whosoever fears Allaah and keeps his duty to Him, He will make his matter easy for him” [al-Talaaq 65:4]
The female nurse also has to be cautious and resign if she cannot achieve what she wants, because both of you are responsible with regard to what Allaah has enjoined and forbidden.