Im watching the original dragonball and its after krillian dies.

Bulma builds krillian a pod so his body doesnt decay (apparently that was a thing they needed to think of in OG dragonball) and they she shrinks him into a capsule!

So clearly, humans CAN be put in capsules. AND they even had pods to preserve people. So whats the risk? Lack of oxygen?

I just thought of something else as well. The fact that they put Krillin in a preservation pod before the capsule, shows that whatever you are storing still functions as it otherwise would. If it didn't, they could just put Krillin in a capsule without the pod in like this micro dimension.

But they put him in the Pod first, so in theory if you had say, a submarine with its own oxygen supply. You could go into the submarine, get turned into a capsule and be perfectly fine as long as you have oxygen!