Burr Cartwright Brundage notes that Aztec children received a form of baptism by fire.
Burr Cartwright Brundage, The Fifth Sun: Aztec Gods, Aztec World (Austin, Texas: University of Texas Press, 1979), 22
Xiuhteuctli, Lord of the year
Xiuhteuctli is one of the most interesting members of the Aztec pantheon. We have already met him as the god of fire who, by his residence in the hearth, defines the center of all things and, as a necessary consequence, the four directions as well. He was the most ancient and venerable of all the gods and sacrifices were always made to him first; it is this primigenial claim which gave him jurisdiction over time itself. He is always depicted as emaciated, bearded, deeply wrinkled, and bent over with extreme age. In ceramic representations he is seated cross-legged on the ground, his head and neck crushed down under the weight of a bowl in which ceremonial fire could be burned. This is the transfiguration of the god commonly referred to as Huehueteotl, the Old God. He was also called Our Father and sometimes Our Only Father. He was the father and mother of all the gods and consequently the source of the divinity. Newborn children were commonly passed through the flames of the hearth and lightly singed as a form of baptism and an acknowledgment of their filiation with the fire god.