Cryonics, as I'm sure you're all aware, has for decades been the best and only shot at a long life in the future for people who die before the advent of rejuvenation biotechnologies capable of reversing the damage of aging. That is a massive number of people, possibly including you and I unless we get our act together - and sadly, all too few will choose to be cryopreserved, even though they have the opportunity and the means. Cryonics is, in essence, a form of indefinite low temperature storage of the body and brain immediately following death. It is carried out with the reasonable expectation, based on present scientific knowledge, that it preserves the fine structure of the brain that stores the information of the mind - you might not be running, but all your data is backed up.
We can envisage the technologies needed to restore a preserved person to active life once again, and none of it is prohibited by the laws of physics. It most likely require a far greater understanding of the structure human brain, the ability to build a new body from scratch, the use of a molecular manufacturing technology base and swarms of nanoscale medical robots, capable of manipulating and repairing cellular machinery - and the computational power to support sophisticated use of these medical technologies. But all of these are foreseeable, and presently being worked on by a range of research groups. It isn't pie in the sky to expect there to be a chance of resuscitation for cryopreserved individuals. Their lives are on hold, but not gone - you are only irrevocably gone if you choose the grave.
But how does a cryopreservation work in practice? How does one go from the last weeks of life to being safely stored in liquid nitrogen, awaiting the future? As I've noted in the past, it takes a fair amount of organization to do well, and the regulatory environment surround end of life choices doesn't make a good cryopreservation any easier - you are not allowed to choose when to do it, and in most jurisdictions no-one is allowed to help you plan your death to be at the time of your choosing either. If you want to learn more about how a cryopreservation tends to unfold, then you should note that cryonics provider Alcor publishes case summaries on a regular basis, as patients are preserved. You'll find some referenced back in the Fight Aging! archives, and here are a couple of recent case summaries:
This past quarter, Alcor cryopreserved two of its members. The first member, A-1408, lived just north of the Tampa, FL area. Alcor team members initiated a standby at the hospital for three days during the time the individual was listed as critical and medical providers anticipated that he might stop breathing. The member stabilized and Alcor ended the standby while continuing to monitor the patient's condition remotely. When his medical condition deteriorated again, Alcor was on the verge of initiating a standby for another member and therefore decided to request Suspended Animation to provide the standby this time.
On the afternoon of the fourth day of the standby (May 26, 2011), the member was pronounced, stabilized and cooled on-site, followed by a field washout. The transport commenced the next morning by commercial airlines and the patient was brought to Alcor with the surgical team at the ready. After the neuro cryopreservation ensued, member A-1408 became Alcor's 105th patient.
Wesley Du Charme authored a book: Becoming Immortal: Nanotechnology, You and the Demise of Death in 1995, which discussed the opportunity for virtual immortality through combining nanotechnology and cryonics. He lived life fully while always looking to the future; he joined Alcor in hopes of living in the far future.
The tests showed that Wesley now had pancreatic cancer with metastases to the liver and duodenum. At this point, the oncologist said that his condition was terminal and nonoperable, and Wesley would not respond to chemo or radiation treatments. When asked how long Wesley had to live, he responded with "...longer than three days, but less than six months."
Given Wesley's greatly weakened condition, the family desired to have him admitted to hospice care in Scottsdale, Arizona, close to Alcor. As Wesley was currently hospitalized, his physician who was supportive of the cryopreservation directives, prescribed TPN (Total Parenteral Nutrition) as a way to increase Wesley's strength and stamina to endure the trip to Arizona. Alcor personnel helped facilitate communication between the hospice facility and the family to finalize the admittance process.
You should read the whole PDF document, and be appreciative of the folk who were thoughtful enough to allow a detailed account of the arrangement of Du Charme's cryopreservation to be published. The end of a life and the terminal breakdown of a body's necessary systems are never pretty, and most people prefer to sweep all of that behind the curtain - and the same goes for the hundred small organizational details that go into managing death and cryopreservation. But if they aren't published, we don't learn.