IMAGINE waking up centuries from now in a world where diseases are eradicated, ageing is reversed, and technology has advanced beyond our wildest dreams.

This is the hope that drives the field of cryonics, the practice of preserving human bodies at ultra-low temperatures in the hope that future technology will be able to revive them.

While it sounds like science fiction, about 500 people around the world have already taken the plunge - literally freezing themselves in time with the dream of a second chance at life.

The Numbers Behind the Frozen Frontier

Currently, the United States leads the world in cryonic preservation, with about 300 people stored at facilities such as the Alcor Life Extension Foundation in Arizona. Alcor also keeps over 30 pets in cryopreservation, as some people hope to reunite with their beloved animals in the future. Another major US facility, the Cryonics Institute in Michigan, houses dozens more.

Outside the U.S., Russia’s KrioRus has preserved around 50 individuals, while in Europe, about 100 people have been placed in cryonic suspension through companies like Tomorrow Bio. These numbers are still small, but interest in the field is growing as technology advances and public awareness increases.

The Science Behind Cryonics

Cryonics works by cooling a legally deceased person to an extremely low temperature - typically around -196°C (-320°F) - using liquid nitrogen. The process begins as soon as possible after death to prevent brain deterioration. First, the body is packed in ice while blood circulation and breathing are artificially maintained. Then, a cryoprotectant, a chemical that prevents ice crystal formation, is introduced to replace bodily fluids. Finally, the body is gradually cooled before being stored in a cryogenic chamber.

The major hurdle? The technology to revive these individuals doesn’t exist - yet. Cryonics proponents argue that future advancements in regenerative medicine, nanotechnology, and artificial intelligence could one day make revival possible. They point to progress in areas like tissue preservation, stem cell research, and brain mapping as indicators that we may eventually develop the ability to repair and revive frozen individuals.

The Ethical and Scientific Debate

Despite its promise, cryonics remains highly controversial. Many scientists are sceptical, arguing that the process causes irreversible damage to cells and tissues, particularly the brain. Without proof that memory and consciousness can survive deep freezing, critics say cryonics is based more on hope than science.

Additionally, there are ethical and legal challenges. Critics question the implications of reviving people in a future they never lived in - one where their families, cultures, and even entire civilisations may no longer exist. Would they be welcomed or seen as scientific oddities? And what about overpopulation or potential resource constraints in a world that may not be prepared for such an influx of reanimated individuals?

Why People Choose Cryonics

Despite these uncertainties, some people see cryonics as their best chance at a longer life. Many are driven by a deep desire to experience the future, while others see it as a way to escape terminal illness with the hope of a cure down the line.

Financially, cryonics isn’t cheap - preservation at Alcor can cost upwards of $200,000, though some people fund it through life insurance. More affordable options, such as head-only preservation (neuropreservation), cost around $80,000. While still expensive, some believe this is a worthwhile investment in the possibility of a second life.

The Future of Cryonics

While bringing frozen humans back to life remains an unsolved problem, research into cryopreservation is yielding advancements that could benefit medicine in other ways. Scientists are already working on preserving organs for transplantation, a breakthrough that could save countless lives.

Whether or not cryonics will ever fulfil its promise remains uncertain. But for those who choose to be frozen, it represents something profoundly human: the refusal to accept the limits of our mortality. Only time - and technology - will tell if their gamble pays off.