Cryogenics is an entire field of physical science. It is the study of matter at temperatures much colder than those that occur naturally on Earth. Cryogenic temperatures are considerably lower than those encountered in ordinary physical processes. There is another field of interest associated with very cold temperature-cryonics. Cryonics is the practice of freezing of people, or just their heads, in liquid nitrogen after death in hopes that one day they can be thawed to the out cured of what killed them. "This could be the most profound revolution in human history. It is the change to live as long as you want." (Goodavage, 1990) Cryonics is not a science. It has little basic in fact. But some people accept Cryonics, because it tells them something they want to believe.
Once you have been declared dead, doctors or morticians will work to keep you cool. They inject you with heparin to prevent blood clots, hook you up to a heart-lung machine to keep oxygen and blood moving through your system artificially, and get you to the cryonics center as quickly as possible.
The optimum time from death to arrival at the center is less than an hour. Some patients have arrived as late as six hours after death.
At the center, your body is put on a table in the perfusion room. A team of three or four technicians work to drain the blood out of your body and inject a cryoprotective agent to get as much moisture as possible out of the tissues, so the organ don't crack during freezing.
The body is then dried and wrapped in a cotton sheet. It is placed, cocoonlike, into a standard sleeping bag, head first, with the open end by the feet tied off. The body is placed in a large brown...