The ruling applied to taking blood from the fasting person is the same ruling as to those who require a blood test.  The blood is taken from anywhere except the head, and regarding cupping- taking blood from the head, the majority say that the fast is not broken by them, as the narration that says: “The man who cups and a man who gets himself cupped break their fast” has not been safe from criticism, if not from a narration point of view then from using it as evidence.