I’m writing a story about someone who is going to be frozen in cryo for about 450 years. He’s frozen in 2120, so the technology is certainly well-developed in his time. I’m thinking maybe the cryo pod he was put in wasn’t built very well, or maybe 450 years is a bit long to be frozen and not the length of time his pod was meant to work for.

I’m wondering what physical and mental side effects he could suffer from, either from being frozen for so many years, or from a not-so-great cryo pod, or both.

I was also wondering if it’s at all possible that he could specifically suffer from some kind of change in his eye color.

I’ve looked at sources online, read about how Fallout and Halo and how some movies handle cryo, but I couldn’t find anything about side effects except confusion and nausea.

Any help would be appreciated :)

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    $\begingroup$ Eye color can change for a variety of reasons ( see Wikipedia's article on Eye Color ). But note a poorly built pod is most likely to kill the occupant and nothing else. I'd suggest you skip that idea entirely and just have your subject be one of the "rare cases who has such-and-such side effects from cryosleep". Don't over-complicate a narrative. $\endgroup$ Jun 3, 2018 at 13:01

3 Answers 3


Even with really advanced cyro-tech it may still be possible to get "freezer-burn" given the length of time the character is to spend in cold storage. The idea is that in some areas the anti-freeze drugs that are supposed to stop cells bursting due to ice crystal formation either A. didn't take properly or B. the dose was low enough that it wore off before the thaw. Tissue not protected by some form of anti-freeze compound would suffer something like frostbite. The tissue most vulnerable to this form of damage would be that with the worse circulation, fingers, toes, the external ear, and especially the eyeball, this damage even in it's mildest form would manifest as burst vessels that would turn the eyes red with blood.

That's the physical, mental issues would be interesting, it would largely depend, I would think, on how long he expected to be out of circulation because after 450 years everyone and everything he'd ever known would be gone so depression and apathy might be expected for a start, the further adrift in time he finds himself the worse I would expect those symptoms to be. Brain damage and associated deficits and psychoses cannot be ignored as logical consequences of extended cyro as well.


First things that comes to mind when thinking about a living organism frozen for so long is: radiation damage.

I am not talking about being exposed to some nuclear incident fallout, but really about constant exposure to natural background radiation. Every living organism has mechanism to immediately repair this damage, but in a frozen organism these mechanisms would be stopped.

When the individual would be awaken all his cells would have to deal with a large damage which is possibly beyond reparable.

  • $\begingroup$ Even radiation sources within the body would be a concern on this timescale. So you can't even say that there is super-shield to block the background radiation. $\endgroup$
    – Harabeck
    Oct 17, 2019 at 19:48

You Die

If frozen solid the side effect is death and decay. Decay occurs much much slower than normal when a body is frozen but "sleep" it is not. It is death. You are dead and you are rotting, just very very slowly. Additionally ice crystals in the cells pierce the cell membranes causing further degradation to the body at a cellular level. This is a complex way to say that you get freezer burned.

Revival from cryogenic storage is nothing short of a literal resurrection except Jesus would be jealous since he didn't have to reverse the effects of a few centuries of DNA and cellular degradation and freezer burn when he did his. We are talking a full head to toe cellular rebuild from the molecular structure on up. There really is no way of predicting what that level of technology's side effects would be because revival from cryogenic storage is pushing the limit of technology into "seems like magic" territory.

One beneficial and guaranteed side effect of regular applications of this process minus the freezing part is functional immortality though. If you can rebuild the body at such a fundamental level you can essentially apply that treatment every so often and effectively be whatever age you want forever. Again, no idea what the effects would be though. We don't even have a hypothesis how it would work beyond a shrug and "maybe nanites?"

Essentially the potential negative side effects can be whatever you like because you are outside the realm of modern science's present scope of understanding.

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    $\begingroup$ But the OP assumption is that the technology is developed. $\endgroup$
    – L.Dutch
    Jun 3, 2018 at 8:40
  • $\begingroup$ We haven't even begun to develop it yet so the fact that we have no idea what the physical or mental effects of such a treatment would be still stands. $\endgroup$
    – TCAT117
    Jun 3, 2018 at 13:46
  • $\begingroup$ en.wikipedia.org/wiki/Cryopreservation#Vitrification - as a matter of fact, we have begun to develop it. $\endgroup$
    – Mołot
    Jun 3, 2018 at 19:22
  • $\begingroup$ Perhaps I was too vague, yes, we have figured out the freezing part, the process which I was referring to that has yet to begin development was the second half, resurrecting somebody from a tank of liquid nitrogen. $\endgroup$
    – TCAT117
    Jun 3, 2018 at 19:33

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