In the Star Wars universe, there exists a carbon freezing process that has been used before to transport frozen gas over long distances. In Cloud City, the carbon freezing process is used for the first time to encase a living person in suspended hibernation.

When Leia rescues Han Solo from his carbonite prison, Leia comments on the onset of hibernation sickness that Han is experiencing:

Leia: "Just relax for a moment. You're free of the carbonite. Shh. You have hibernation sickness."

Han: "I can't see."

Leia: "Your eyesight will return in time."

However, earlier, Lando Calrissian comments on how carbon freezing has never (to his knowledge) been used on humans before:

"Lord Vader, we only use this facility for carbon freezing. If you put him in there it might kill him."

How does Leia know that Han is experiencing hibernation sickness from being frozen in carbonite, if Han is the first person in history to go through that process? Even if hibernation sickness is not exclusive to carbon freezing, how does Leia know that it is specifically what Han is experiencing?

  • 22
    Maybe other people have been frozen in and rescued from carbonite while Han was stuck in there. Maybe the Rebellion even did this intentionally, to rehearse rescuing Han. (Or maybe she was just being reassuring, and actually didn’t have a clue.) Commented Nov 16, 2015 at 15:53
  • 5
    we see carbonite being used to freeze other people in disney canon. granted, leia probably doesn't know about that specific instance. we don't know how often carbonite is used galaxy-wide for such purposes.
    – phantom42
    Commented Nov 16, 2015 at 16:00
  • 18
    my interpretation of the scenes involving Han being frozen (and I have nothing else to back this up hence this is a comment, not an answer) has always been that freezing people in carbonite had been done before, but not using the facility at Cloud City, which was only intended for use with goods. Commented Nov 16, 2015 at 17:16
  • 7
    I don't think Lando's quote is to indicate that no one has ever been frozen in carbanite before. I think what Lando is actually saying is that no one has been frozen at his specific facility before. Take current rocket design: we build "simple" rockets to send objects into space, and then over-engineer the crap out of rockets that send people up to space. I think the same principle applies here: Cloud City's facility is design to freeze non-living material, and then Vader shows up wanting to freeze a couple of people, which it wasn't designed to do with an assurance on safety.
    – Ellesedil
    Commented Nov 16, 2015 at 20:34
  • 5
    I think @Ellesedil has it right. The quote 'we only use ***this*** facility for carbon freezing' doesn't seem to imply that no facilities exist in that could be used for carbon freezing life forms. After all C-3PO seemed pretty confident that if Han survived the freezing he should be perfectly safe. How would C-3PO possibly have known that, if it hadn't been done before.
    – Zoredache
    Commented Nov 16, 2015 at 22:30

4 Answers 4


I think I found a pretty good quote to answer my own question.

Immediately after freezing Han Solo in carbonite, Darth Vader remarks to Lando:

Vader: "Well, Calrissian? Did he survive?"

Lando: "Yes, he's alive...and in perfect hibernation."

If we can assume that Leia is within earshot of this conversation (which she most likely would be, as she is still at this point in the same room as far as I can remember), we now know that Leia knows that Han Solo is now in a form of hibernation. Since Leia already knows about the effects of hibernation sickness, it makes perfect sense that she would "put two and two together" by the time that she un-freezes Han and figure out that Han would, to the best of her knowledge, be experiencing a form of hibernation sickness.

As an interesting side note, Leia might already possess a limited knowledge of some effects of carbon freezing (in the Legends Canon, anyway) as the Alderaanian Medical Association has done at least limited research on it.

  • 4
    Wouldn't Vader be able to sense Han's survival? Commented Nov 16, 2015 at 17:11
  • 6
    @AdamLawrence: Not necessarily. He can sense other people who are strongly force-attuned (e.g. Luke, although that may also be due to the genetic link), but Han is not. Also, it's entirely possible the carbonite would interfere with any such abilities. Commented Nov 16, 2015 at 17:54
  • 15
    Even if Leia didn't already know about hibernation sickness, Leia (or someone) also would have studied up (wouldn't you think?) on the likely effects as part of the rather elaborate planning for Han's rescue.
    – Dronz
    Commented Nov 16, 2015 at 18:30
  • 6
    Isn't the AMA (Alderaanian Medical Association) the same group who has Broken Heart as a possible cause of death? Commented Nov 16, 2015 at 23:15
  • 5
    I think that's just the droid on Polis Massa. It was reading too many shlocky romance novels in its free time. This is why computer-based medical personnel are supposed to be off during their off hours.
    – Wolfie Inu
    Commented Nov 17, 2015 at 6:25

This is never sufficiently explained in Disney Canon. Carbonite Freezing of people has been done before, but there's no evidence that Leia would have known about the results or effects.

However, in Legends Canon, this can be handwaved pretty easily.

Leia explains that Han is suffering from Hibernation Sickness, but does not specify that it is specific to, or only caused by being frozen in carbonite.

In fact, Hibernation Sickness is caused by being in suspended animation. Wookieepedia mentions a few methods of being put into suspended animation, such as sleeper ships and Sith techniques.

In Legends canon, since this is not a new concept or affliction, it's entirely possible/likely that she simply knew what sort of effects being in suspended animation would cause.

  • 3
    That's what I was thinking. Being a princess who is well-versed in long-range space travel, Leia is probably knowledgeable, at least to a point, about different methods of suspended animation.
    – Paul Omans
    Commented Nov 16, 2015 at 16:31
  • 9
    Of course @PaulOmans, Leia is simply awesome. She's also a redneck: She's not afraid to shoot someone in the face, and she was in love with her brother...
    – Daniel
    Commented Nov 16, 2015 at 16:43
  • 1
    At the last paragraph: Or alternatively that the group researched it specifically as part of their planning the rescue. They clearly did go through quite a bit of planning, after all.
    – jpmc26
    Commented Nov 17, 2015 at 1:00
  • 1
    It's also worth pointing out that in the BioWare & LucasArts Star Wars MMO (whatever level of canon that is), there is successful/safe carbonite freezing and thawing of a lifeform in approximately 3650 BBY. So depending on canon level, this procedure has been around for at least a few millennia.
    – TylerH
    Commented Nov 17, 2015 at 17:38

We don't know for sure, but it's apparent that some time has passed between the end of Empire Strikes Back, when Han was frozen, and the beginning of RotJ, when he is rescued. Boba Fett delivers Han to Jabba, Jabba has time to make him into a decoration in his palace. Leia and company also had to plan the rescue operation, which obviously began at least some time before RotJ starts, because Lando is already working as a guard in Jabba's palace at the start of the movie. I think it's safe to assume that just like every other aspect of the rescue was planned, they also had to have some idea of what shape Han would be in after being unfrozen and that Leia did some studying up on carbonite freezing during that time to answer that question.


In Canon, Leia is frozen in carbonite by Darth Vader after the events of The Empire Strikes Back:

Panel from Star Wars (2020) #3 showing Leia in carbonite

(source: Star Wars (2020) #3)

She escapes not too long after:

Panel from Star Wars (2020) #4 showing Leia unfreezing from carbonite

(source: Star Wars (2020) #4)

While she is only frozen for a short time and doesn't suffer any obvious side effects, this at least shows that she has first-hand experience with the feeling of being frozen and unfrozen in carbonite.

Additionally, it's established in Canon that carbonite has long been used for human transport, and that the side effects are well known:

Before the invention of the hyperdrive, some space travelers used carbonite to endure long voyages. But the side effects are brutal. Since a common side effect was death, Solo is lucky to have only exhaustion, weakness, dehydration, dizziness, memory loss, and blindness.

(source: Return of the Jedi: Beware the Power of the Dark Side!)

  • 5
    This is a monumentally dumb story idea.
    – Buzz
    Commented Nov 7, 2021 at 6:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.