Most cemeteries require the casket be placed into an outer burial receptacle.
These receptacles are made of concrete or of various kinds of metals and provide a measure of protection against the weight of the earth compressing the casket and may also provide a measure of protection for the casket against the elements. Most crematories will require the remains to be placed into a rigid container for the health and safety of their employees. The human remains are transported to a medical school for the purpose of medical research and training. Usually arrangements with the medical school need to be completed before the death has occurred to be sure the person meets their criteria. Your funeral director must also be made aware of this at the time of death because it may affect his method of preparation.