I have arrangements to be cryopreserved in the event of my clinical death, and I encourage everyone reading this to make similar arrangements. How cryopreservation works, and why people should sign up, is covered in great detail in the Alcor FAQ (linked below). However, for those who don’t have time to read the whole thing (it’s rather long), I’ve put together a very simplified summary here.

– Cryonics freezes terminally ill people who are clinically “dead” (no heartbeat or breathing) in liquid nitrogen, so they can be warmed up and revived with future medical technology. At liquid nitrogen temperatures, all metabolism stops, so the body is preserved intact and does not decay further. Cryonics is the only way to avoid eventual death from old age with current technology.

– Just because someone is at room temperature, and has no heartbeat (clinical death), does not mean they are permanently “dead”. People in this condition are revived routinely in hospitals. In fact, surgeons will deliberately cool a patient’s body and stop the heart for certain types of brain surgery (deep hypothermic circulatory arrest).

– For a person under 40 with no serious illness, being signed up for cryonics costs around $30-$150 per month, depending on various options. It is only expensive if you, or a family member, procrastinate and delay signing up until shortly before death. Please don’t do that.

– All major cryonics organizations are non-profit. No one has ever made money off cryonics except modest below-market salaries, and frequently not even that.

– At a best guess, a “clinically dead” person can last a few hours without cooling, or a few days with only water-ice cooling, before the cells self-destruct and they are truly and irrevocably dead. However, this is just a guess, and the odds are better the sooner cryonics is performed.

– Cryonics, if properly done, does not cause ice to form. Ice crystals, of course, would damage the cells. Instead, cryoprotectants are used so that tissue forms a glass-like solid at low temperatures.

– As of now, the largest tissue to have been fully cryopreserved (below dry ice temperature) and successfully revived is a rabbit kidney. (Human embryos, of course, are routinely cryopreserved.) Research is ongoing into how to revive larger tissues and entire animals.

– While the early days of cryonics saw many mistakes, and some patients were thawed out due to negligence or funding issues, this has not happened in almost forty years. Cryonics organizations are now Properly Paranoid about ensuring indefinite freezing and permanent maintenance income. Fortunately, cryonics patients require minimal maintenance (just a liquid nitrogen top-off every month).

– In addition to general patient care funds, one can set aside assets to be used for revival, or for life after revival. This is done through a special type of trust.

The Full Alcor FAQ

A tour of Alcor and cryonics procedures