Question: is cryogenic freezing of humans possible?

Elliot Jokl answered on 20 Jun 2016:

Thanks for the question!

In theory, it might be possible, but the practical problems that you need to overcome to get it to work are quite tricky! I’m not sure if it is something we can realistically do

One of the biggest problems is that freezing things can cause ice crystals to form, which cause damage to cells so they won’t work properly when you try to thaw them out again. That is what happens when people get frostbite if they stay out in the cold too long, which can cause people to lose fingers and toes. But in this case, every part of the body would have frostbite, which would be, bluntly, a disaster.

To stop the ice crystals from forming, you have to freeze something very, very fast – which is hard to do because people are very big. That also means the insides are slower to freeze than the outsides which is also bad. There are also chemicals that can help prevent ice crystals from forming, but these are very toxic so it is difficult to imagine how they could be used without doing more harm than good.

Thawing people would also be pretty tricky. You know how if you put water on an ice cube, the ice will crack? That could happen to a frozen body when it is being warmed up too.

The other tricky business is how to get organs up and running again. At the moment, people usually freeze dead people. Even if the freezing and the thawing worked well, you still only have a dead body. And if you freeze a living person, we don’t really know how well the organs will work when they are thawed again. So that part of things is a big question mark.