Yucatan Before and After the Conquest, by Diego de Landa, tr. William Gates, , at sacred-texts.com
In the year whose dominical was Cauac and the augury Hosan-ek, after the election of the one to serve as president had been made, they made an image of the demon named Ek-uvayeyab, and carried this to the piles of stone on the West, where they had left the other the year before. They also made a statue of a demon called Vacmitun-ahau, which they put in the president's house in a convenient place, and from there went all together to where the image of Vacmitun-ahau stood, having the road thither all properly prepared. On arriving the priest and the chiefs offered incense, as they were accustomed, and cut off the head of a fowl. After this they took the image on a standard called yax-ek, placing on the back of the image a skull
and a corpse, and on top a carnivorous bird called kuch ['vulture'], as a sign of great mortality, since they regarded this as a very evil year.
They then carried it thus with their sentiment and devotion, dancing various dances, among which was one like the cazcarientas, which they thus called the xibalba-okot, meaning the dance of the devil. The cup-bearers brought to the road the drink of the chiefs, which they drank and came to the place of the statue Vacmitun-ahau, and then they placed before it the image they brought. Thereupon commenced the offerings, the incense, and the prayers, while many drew blood from many parts of the body, to anoint the stone of the demon called Ekel-acantun; thus the fatal days passed, after which they carried Vacmitun-ahau to the temple, and Ek-uvayeyab to the place of the South, to receive it the next year.
This year whose sign is Cauac and which was ruled by the bacab Hosan-ek, they held as one of mortality and very bad, according to the omens; for they said that many hot spells would kill the maize fields, while the multitudes of the ants and the birds would eat up the seeds that had been sown; but since this would not happen in all parts, in some places they would lack food, and in others have it, though with heavy labor. To avoid this the evil one caused them to make four demons called Chichac-chob, Ekbalam-chac, Ahcanuol-cab, Ahbuluc-balam, and set them in the temple where they should offer incense, and burn two balls of the milk or resin called kik, together with some iguanas, and bread, a miter, a bunch of flowers, and one of their precious stones. After this, to celebrate the festival, they made a great vault of wood, filling it aloft and on the sides with firewood, leaving doors to enter and go out. Then the most of the men took each two bundles of rods, very dry and long, tied together, and a singer standing on top of the firewood sang and made sound with one of their drums, while those below danced in complete unison and devotion, entering and leaving the doors of that wooden vault; dancing thus until the evening, each left there his bundle, and they then went home to rest and eat.
When the night came on they returned, and with them came a great crowd, because this ceremony was held in great regard. Each then took his bundle of rods, lit it, and each for himself put fire to the firewood, which burned high and quickly. When only the coals were left, they smoothed and spread them out; then those who had danced having come together, some of them began to walk unshod and naked from one side to the other across the hot coals; some of these came off with no lesions whatever, some came burned or half burned. In this way they believed to lie the remedy against the ills and bad auguries, and that this was the service most acceptable to their gods. After this they went off to drink and get intoxicated, for this was called for by the customs of the festival, and by the heat of the fire.