The practice of freezing your body after death for possible future revival is called cryonics. It’s often confused with “cryogenics,” which is simply the broader science of producing very cold temperatures. Cryonics specifically refers to preserving human bodies (or just the brain) at extremely low temperatures, around -196°C, in the hope that future medical technology could one day restore the person to life.
How Cryonics Actually Works
Cryonics can only legally begin after a person has been declared dead. In practice, this means a medical professional must confirm that the heart has stopped and brain stem function has ceased. Once that legal threshold is crossed, the process starts immediately, because every minute of delay causes more cellular damage from oxygen deprivation.
A standby team begins CPR while packing the body in ice to drop the temperature as quickly as possible. Medications are administered to slow the effects of oxygen loss and prevent blood clots. The goal at this stage is simply to buy time.
The critical next step is called vitrification. Rather than simply freezing the body (which would form ice crystals that shred cells from the inside), technicians replace blood with chemical solutions called cryoprotectants. These compounds work by bonding to water molecules and disrupting the normal process of ice crystal formation. Instead of freezing into sharp crystals, the body’s tissues transition into a glass-like solid state. Think of it as turning the body’s water into something closer to hardened syrup than ice.
The temperature is then dropped rapidly to about -110°C, then lowered more slowly to -196°C. That slower second stage helps prevent fracturing of tissue, particularly in the brain. At this final temperature, all chemical activity essentially stops, meaning the body could theoretically remain preserved for centuries.
Whole Body vs. Brain Only
Cryonics providers offer two main options: whole-body preservation or neuropreservation, which preserves only the head. The logic behind neuropreservation rests on the idea that your identity, your memories, personality, and sense of self, is encoded in the physical structure of your brain. If those neural connections can be kept intact, the thinking goes, a future technology could potentially reconstruct or provide a new body.
The cost difference is significant. At Alcor, the largest provider in the United States, whole-body preservation costs $220,000 while neuropreservation costs $80,000. Most members fund this through life insurance policies, which brings the monthly cost down to roughly $25 to $75 depending on the option and the person’s age. Annual membership dues at Alcor are based on your age when you join, calculated at $15 multiplied by your current age for anyone 19 or older.
Where Cryonics Facilities Exist
Only a handful of organizations in the world offer cryonics services. Alcor, based in Scottsdale, Arizona, is the most well-known and maintains standby teams across the United States. The Cryonics Institute, based in Michigan, is another major American provider. In Europe, Tomorrow Bio operates out of Germany and Switzerland, running mobile cryoprotection units (essentially ambulances equipped as surgical suites) and storing patients at a facility in Switzerland. Each organization differs in its preservation protocols, pricing, and approach to long-term storage, but all follow the same core principle of rapid cooling and vitrification.
The Scientific Reality
No one has ever been revived from cryopreservation. That’s the single most important fact about cryonics, and it’s worth stating plainly. While scientists can successfully freeze and thaw individual cells, embryos, and small tissue samples, scaling that up to whole organs or entire bodies remains far beyond current technology.
The challenges are stacked. Different cell types and organs respond differently to cooling and to cryoprotectant chemicals, yet in cryonics the entire body undergoes one uniform procedure. Prolonged storage at extremely low temperatures can cause large organs to crack or fracture. The cryoprotectant chemicals themselves are toxic to cells at the concentrations needed to prevent ice formation. And even if all physical damage could somehow be repaired, the person would still need to be cured of whatever killed them in the first place.
Revival would require repairing damage from oxygen deprivation, chemical toxicity, thermal stress, and potentially ice formation in tissues that weren’t perfectly vitrified. No studies have attempted to cryopreserve and revive even a whole animal, let alone a human. Researchers in the field openly acknowledge that revival remains the most problematic challenge, one that currently rests more on hope than on demonstrated science.
The Ethical Questions
Cryonics sits in a unique legal and ethical gray zone. A cryopreserved person is legally dead, yet the entire premise of cryonics is that they might not be permanently dead. This raises the question of whether someone in a cryopreservation tank should be treated purely as remains or as something closer to a “potential person” with some claim to rights.
Critics also point to the cost and resources involved, questioning whether it’s reasonable to indefinitely maintain bodies on the speculative chance of future revival. Supporters counter that cryonics is a personal choice funded privately, comparable to any other long-shot bet on future technology. The debate remains unresolved, in part because the science hasn’t advanced far enough to settle it one way or the other.
What Cryonics Is Not
Cryonics is not the same as cryotherapy (cold treatments used for muscle recovery or skin conditions) or cryosurgery (using extreme cold to destroy abnormal tissue like warts or tumors). It’s also distinct from cryopreservation of eggs, sperm, or embryos for fertility purposes, though the underlying science of protecting cells from freezing damage overlaps. The key difference is scale: preserving a single cell or a cluster of cells is routine medicine, while preserving an entire human body with the goal of future revival is speculative and unproven.