If a woman had an abortion before 80 days of pregnancy, then the blood she passes is not the blood of Nifas which does not stop her from praying and fasting, but she has to do Wudu for each prayer. If the abortion took place after the soul was breathed into the foetus, then the blood is definitely Nifas and she cannot pray or fast.

It is permissible for civil defense workers to break their fast in extreme heat in order to rescue the injured, but it is preferable not to break the fast, except in cases of necessity, and they should make up that day.