https://classesv2.yale.edu/access/content/user/haw6/Vikings/Widukind.html
	The Danes were of old Christians, but they nevertheless served their idols in pagan rites. There was, however, a quarrel about this cult of gods at a banquet attended by their king. The Danes asserted that Christ certainly was a god, but that other gods were greater than he, since they in fact made themselves known to mortals through greater signs and portents. A cleric by the name of Poppa, who now lives a pious life as a bishop, argued against this, stating that there is only one true God, the Father with His only begotten Son Jesus Christ, our Lord, and the Holy Spirit, and that the idols are demons and not gods. King Harald, who is said to be quick to hear but slow to speak, asked him if he himself wanted to testify to this faith. He answered without delay that he wanted. The king ordered that the cleric would be guarded until the next day. The following morning he ordered that a great weight of iron be heated in the fire and he commanded that the cleric carry the glowing iron for the sake of his catholic faith. The confessor of Christ grabbed the iron without hesitation and carried it as far as the king determined. He then showed his unhurt hands to everyone, proving the truth of the catholic faith. Thereafter the king, who had been converted, decided that Christ would be the only god to be worshiped, and he ordered that his people should reject the idols. From then on, he held the priests and other servants of God in appropriate respect.


might be able to do by getting your hands wet first:

https://www.youtube.com/watch?v=yTOCAd2QhGg


are there "tricky" explanations for some of these "miracles"?