A ruling by a High Court judge allows a 14-year-old girl who died from a rare form of cancer in October, to be frozen and preserved in a cryonics facility in the US. The judge, Justice Peter Jackson, made clear the ruling was not about the ethics of cryonics itself but a dispute between the girl’s parents over how her body was to be treated after death. Her mother supported her daughter’s wish to be preserved; her father was against the plan.

But what exactly is cryonics? And will it ever become the norm given its current status as a legal, scientific and ethical minefield?

Despite its strange-sounding name, the concept of cryonics is pretty simple: dry ice is immediately used after death (or rather, when someone is “legally dead”) to cool the body to low temperatures. After this, substances such as antifreeze are injected into the body to prevent the formation of ice crystals inside the cells before the body is frozen in liquid nitrogen at very low temperatures.

And as far as preservation goes, this is where it stops. Most researchers in this field are figuring out how a successful revival would be carried out once medicine has caught up with this field, and place faith in nanotechnology – where the frozen cells can be brought back to room temperatures safely.

It should be noted no human organ has been frozen cryogenically and then successfully brought back to functional existence at safe temperatures.

The real challenge is preventing a build-up of ice inside the cells. This is because water expands when it freezes, therefore ice crystals can cause cells to burst. Very few organisms (plants, animals or bacteria) in the world are able to survive in such harsh conditions, with an even smaller group being able to thrive in such environments (known as extremophiles).

One example is the insect species known as mountain (or cave) weta. These New Zealand natives are able to manage freezing temperatures because their bodies contain specialised proteins that prevent ice crystals forming, therefore allowing them to slowly return to life as normal once the winter hibernation period is over.

But there may never be a true possibility of being brought back to conscious existence once your body (or brain) has been frozen.

It’s hard to pin down the exact number of people cryogenically stored due to the private nature of the few facilities offering the service. The most famous name is Alcor in the US state of Arizona. They currently hold 148 people (or “patients”, as cryonic facilities like to call them) with over 1,000 members having already made all of the necessary legal and financial arrangements for future preservation at Alcor.

The other reason why cryostasis remains a niche option is due to the significant costs involved. After all, people have to pay to fund the necessary research to examine their (potential) future revival. Although there isn’t a UK-based cryonics facility, Cryonics UK is a charity aiming to help people with the preparations involved in freezing and transferring the body to foreign storage facilities.

This week’s ruling and other recent cases show that many who opt for their bodies to undergo this form of storage have lived in an age where medicine couldn’t treat their severe and rare illnesses. It’s easy to dismiss the whole field as a fad or delusion for those simply “scared of death”, but cryonics is taken seriously by some of the most-respected scientists today, signified by the establishment of the Brain Preservation Foundation with the help of former Harvard University researcher Dr Kenneth Hayworth. Earlier this year, Japanese scientists were able to bring back tardigrades (otherwise known as water bears) back to life after being frozen for 30 years.

It’s striking that the UN and other entities take the threat of robotic death seriously and are establishing safeguards to prevent such a future – yet cryonics remains an equally niche but mostly untouched issue. Ethicists and scientists are the only ones willing to contemplate a potential future where we could “bring back the dead”, so to speak.

“Death” can have multiple definitions in the world of cryonics. That’s where the waters become extremely muddy: not knowing what death actually is, and the idea of consciousness. Will it become a social norm to revive humans in the future? Should humans die like everything else in this world?

Let’s not forget the cold, hard facts at play. The world’s population currently stands at over seven billion. Medium projections by the UN’s Department of Economic and Social Affairs forecasts an increase to over 9.7 billion in 2050, followed by a further increase to 11.2 billion in 2100. Many of those in that last number who will be alive in 2100 are probably with us today.

This will mean we have to reindustrialise our food and energy production in new, innovative ways not just for the world we have today, but plan for the 22nd century (assuming certain world leaders haven’t nuked us to permanent death by that time). We also can’t ignore the need to alter our social care systems to take care of ageing populations around the globe. And I haven’t even mentioned the effects of global warming, which continues to shape our world and biodiversity in ways we barely know.

Add to that a world where humans could possibly be revived. Would a person in cryostasis today, quickly remedied of their diseases through future medicine (many of those preserved have passed away due to incurable illnesses), adapt to a new age so easily? Will they have any friends or family with them to live a new, happy and productive life?

Whenever the topic of human preservation surfaces, I always end up thinking about two things: stories of (sometimes wrongly-convicted) prisoners returning to the outside world after years of seclusion, and those campaigning for euthanasia.

Many ex-prisoners find it impossible to adapt to their new-found freedom. Of course, with cryonics we’re talking about a brain that hasn’t experienced seclusion and remains unaffected by debilitating routine.

And with regards to euthanasia, the subject of preservation brings up similar challenges: under what circumstances should people be able to determine the end of their life and whether humans have the right to (here we go…) “play God”.

Maybe those who object to the idea of cryonics are scared not simply of death but of living for too long. We often delay talking about death with distractions and blind optimism. But cryonics brings up our need to plan for a future that is more challenging than any of our favourite sci-fi novels and films can prepare us for. And we have to start planning now.