Mummification can also occur naturally.

A high temperature, especially when aided by air currents, as in the tropics or inside a chimney, will prevent bacterial decomposition, and thus prevent putrefecation. New-born babies, being sterile and less likely to decompose, are more likely to mummify.

A progressive drying of the tissue then occurs, resulting in leathery hardening and shrivelling of the skin, drawing it tight over the skeleton.