Will an adulterer be given a burning ember for each act of fornication on the Day of Resurrection, including a lustful gaze?

There is no mention in the Sunnah or the books of the scholars indicating that a burning coal is placed on the fornicator for each act of fornication. This is one of those matters that are tawqifiyyah (dependent on divine text) and require an authentic legal text. Fornication is one of the worst abominations, and the Prophet, peace and blessings be upon him, saw the punishment of fornicators in the furnace during his vision. The mentioned punishments are for fornication of the private parts. As for the fornication of the limbs, it is a minor sin (lamam) and its perpetrator deserves punishment if he does not repent from it.