His suit keeps him at like 4 degrees Kelvin, and oxygen freezes at 54.36 K. At this temperature, nothing works the way it works for the rest of us. Does he need to breathe? Does he eat oxygen to survive? What other changes to his physiology keep him alive and functioning at such a temperature?
Don't ask, it's Science!
Seriously, I have often wondered. It's quite clear his body works very, very differently.
Went into this before, but I maintain AZ is immortal, and will survive the heat death of the Universe. Good thing he is cool with being alone.
I would have to imagine breathing works much differently for him. We are talking comic logic too so science doesn't always fully apply.
Yeah, I think he survives because comics. He should probably be pretty frozen solid (and prone to shattering) otherwise, I'd've thought...
“Look, all I know is fire gets all weird around me” seems like it should sum up many other phenomena as well.
I see what you did.
"Because comics" isn't really that cool an answer. Comics tend to come with explanations of how powers work. Like, does anyone remember The Official Handbook of the Marvel Universe? A lot of the explanations were silly, but the writers did set out to go well beyond "because comics" to justify the powers each character had.
Like I am sure Christopher has a more interesting answer to this question than "It's comics, don't question it."
And just to be clear I have fully bought into Absolute Zero functioning. I just want to know how. :) I am not trying to nitpick or criticize.
Outside of some terrible events AZ typically has his helmet on. Maybe that helmet contains a breathing apparatus.
Ooh, maybe he walks around making the same breathing noise as Darth Vader...
So Absolute Zero must be kept cold to survive. Anything he touches or eats that’s above his body temperature would be like a hot poker and probably cause him massive internal damage. Anything he eats or breathes also has to be the temperature of his body. There’s no way around that.
His bio on the web site says that anything above the temperature of liquid helium feels like fire to him, and also that the suit is “capable” of maintaining absolute zero temperature. Let’s take the latter as a statement of capability and not what Abs usually runs it at. He needs <~4 K. Though he clearly can survive limited times of exposure to room temperature, given that he’s depicted on a number of cards with portions of his suit missing. I doubt he was very comfortable, but at least this is survivable.
I see no reason why he couldn’t still eat food, provided it came into contact with his body by way of cryogenic freezing and he didn’t open up the suit. Breathing is the problem. Maybe Absolute Zero can tolerate just-barely-liquid oxygen, at 55 K. Then he could be immersed in LO2. Solid O2, though, I’m not sure how he would manage. We know he can get out of the suit inside the cryo chamber, so it’s not a mechanical means.
Here’s what I think: solid oxygen is much more dense than gaseous oxygen. The density of liquid oxygen is ~1000x higher than gaseous oxygen, and a human breath only extracts a few % of oxygen from the air. So Absolute Zero, if he drinks liquid oxygen or eats solid oxygen, would need to do so about 10,000x less frequently than a normal human breathes. Let’s say I breath once per second when I exercise: that works out to eight times a day for our freezing friend. He can just crunch and inhale (they still have to go to his lungs!) some oxygen dust while he’s in the cryo-chamber, and he doesn’t have to breathe at all when in combat. His slow metabolism will be working on the solid oxygen sitting in his lungs all day long.
How does that distribute to his body properly if he is eating oxygen? I could be wrong but I've never heard of a person who could live off eating their oxygen. His lungs have to be involved to some degree.
Agreed…I got less sloppy with my terminology as I got writing:
I applaud your pseudo-science explanation! It's believable enough for me anyway.
How about this,a function of the suit is that it is has a mechanism that supercooles the oxygen the ~ 90 K needless so As can breathe it?.I know it is possible to supercool O2 and keep it gaseous but :90 K is a big ask.Alternatively AZ has gas O2 @ .1463 kPa, 54 K.storered and the suit simultaneously cools the 50 K needed and gets the O2 to 1 bar while keeping the Oxygen gaseous.Not possible with normal science but with superscience you could do it
Why bother breathing? Perhaps the suit is connected to his bloodstream, and artificially infuses his red blood cells with oxygen, skipping the regular breathing process entirely.
He doesn't breath. Or eat. His body directly converts thermal energy into bio-energy. In normal temperatures, the overload from that process causes pain. If it's cold, there's less ambient thermal energy to convert, so it's more comfortable.
The suit facilitates the process by regulating the temperature around him and providing safe ways to vent off excess energy. He still breathes out of habit, but he doesn't get anything from it
Anyway, that's why fire gets all weird around him.
I like that explanation .It's very cool.The suit probably also has a supply of He to allow Az to talk, and the curl chamber is probably 100 % He.While in the chamber Az uses the ability you describe to cause the He near him to condense,one it does a the liquid is drained away and quickly boils and can be pumped back in as a gas,Thus Az is immortal while the chamber functions
I really like this post. Thanks. 
Wait, helium? So are you telling me that AZ has a permanent munchkin-squeaky voice?
Yep but luckily for him the suit has a James earl Jones setting that makes him soon cool
But we do know that he can get out of the suit, in the cryo chamber. That’s why I think the suit doesn’t mechanically provide him what he needs.
I still like the idea that he can huff powdered solid oxygen in the cryo chamber, and be set on breathing for the rest of the day. He’ll just slowly metabolize what he inhaled that morning.