Cryonics: What It Is and What Science Says

Cryonics is one of the most debated ideas in the whole subject of death: the hope that a person who has died might be stored and brought back someday. This article explains what it is, what it costs, and what scientists say about it.

What is cryonics?

It is the practice of preserving a person at extremely low temperatures after legal death, hoping that future technology can repair the body and restore the person to life. Some providers preserve the whole body, and some preserve only the head or brain. ScienceInsights notes that cryonics organizations call the preserved people “patients,” not dead people, seeing the preservation as a pause rather than an ending.

How does it work?

Only after legal death. The process cannot begin until a formal pronouncement of death, according to ScienceInsights, and courts in several places have confirmed that legal death matches medical death. Cryonics teams often stand by in the person’s final hours, ready to begin immediately, because every minute of delay causes more damage. The Smithsonian reports that the team moves the body into an ice bath and replaces the blood with an organ-preserving solution. The goal is “vitrification”: replacing the water in tissues with chemical solutions that turn into a glass-like solid instead of forming ice crystals.

Who offers it, and what does it cost?

A small number of organizations, mainly the Alcor Life Extension Foundation in Arizona and the Cryonics Institute in Michigan. The Smithsonian counted 199 people preserved at Alcor in 2020. A later ScienceInsights report lists 234 patients at Alcor and 250 at the Cryonics Institute. These figures change, so check the providers for current ones. ScienceInsights gives Alcor’s prices as $80,000 for the head (neuropreservation) and $220,000 for the whole body. The Cryonics Institute’s basic preservation starts at $28,000 to $35,000, but adding a standby team and field treatment brings it to $106,000 to $128,000.

Does it work?

Nobody knows how to revive a preserved person. The Smithsonian states plainly that no cryonics organization knows how to bring its patients back, and that there is no evidence human cryopreservation actually works. Advocates point to successes with freezing and thawing sperm, embryos, and stem cells. Bionity’s encyclopedia entry notes that scientists and cryonics advocates both agree that reversing human cryopreservation is not possible with any near-term technology. Those who believe revival may someday work point to future technologies such as advanced bioengineering and nanomedicine.

What does the scientific community say?

The Society for Cryobiology, the professional group for scientists who study low-temperature biology, says that the knowledge needed to revive whole mammals after cryopreservation does not currently exist. ScienceInsights quotes it as describing cryonics as speculation or hope, not science. Freezing and thawing small cells, such as sperm and embryos, is real, but preserving a whole person and restoring them is a different and unproven matter.

What are the legal and ethical questions?

Several. If cryonics is treated as a medical procedure, it starts only after legal death. ScienceInsights notes that because the dead have no legal rights, disputes over what happens to a preserved body fall into unclear legal territory. Some medical and legal professionals have been skeptical or hostile, as the Smithsonian reports.

What should families know?

That the timing is unusual. Because a cryonics team starts right after legal death, people who have arranged it need their families and care team to know in advance. See How Does a Doctor Know Someone Is Dead? and Right of Disposition Explained for how decisions about the body are made. For the philosophical side of the question, see What Do Philosophers Say About Death?.