What is cryogenics, as seen in Silent Witness?

While some viewers will no doubt be vaguely familiar with the concept of cryogenics, others might be left at a loss. With that in mind we've provided a brief explainer here...

What is cryogenics?

Although frequently referred to as 'cryogenics' in popular culture, the correct name for the procedure is actually cryonics.

Essentially, it refers to the storage of a dead body at extremely cold temperatures, such that is frozen, with the hope that it might be possible to restore life to the corpse at some unknown point in the future.

How does it work?

The idea is that the freezing temperatures, which are set at a level below -130 degrees celsius, will preserve enough brain information in the deceased person that they could possibly be revived. Those who believe in the practise state that there is no fundamental barrier to recovering information content provided that the structure of the brain is kept intact.

Is it legal in the UK?

Yes, cryonics is legal in both the UK and the USA – where around 250 people have been cryopreserved since 1967, although, contrary to a common myth, Walt Disney is not amongst them!

According to the Human Tissue Authority, "There are no laws in the UK that are specifically targeted at cryonics, and it is not currently regulated. However, there are some areas of the law that do have some impact on cryonics, these work on the basis that a patient undergoing the cryonics process has died, so is treated as a dead person."

Though cryonics is not banned, there are a lot of barriers to in the UK. If there's a court-ordered postmortem, that'll delay the point at which the cryopreservation can begin – potentially making it totally impossible – and hospitals are not legally obliged to cooperate with the process.

The HTA also notes: "As there are no cryonics facilities in the UK, your body must be transported to a facility in the United States or Russia." The law says that the body can only leave the country at least four days after the coroner is notified, and a death certificate must be provided, so that's an added complication in a procedure that needs to be carried out as speedily as possible.

Is there any realistic chance of being brought back to life?

On the whole, scientists are extremely sceptical about cryonics, and it is largely regarded as a pseudoscience.

Even if the correct scientific discoveries were made to being people back to life, it is highly likely that the companies responsible for storage would have gone out of business by this point - and the bodies defrosted and disposed of.