One of the important duties of an Aztec priest centred on the maintenance of the sacred fire, making sure that it would burn perpetually. A new fire was ritually kindled during the dedication of new buildings. The two festivals of Xiuhtecuhtli coincide with the two extremes in the climatological cycle, the heat of August and the cold of January. Once every 52 years, at the end of a complete cycle in the calendar of the Aztecs, fire was ceremonially transferred first from temple to temple and then from temples to homes.

The god of fire appears in various representations and guises, one of which depicts him as a toothless old man with a stooped back, carrying an enormous brazier on his head. His insignia was the Xiuhcóatl, or serpent of fire, characterized by a nose of horn, decorated with seven stars.