system
Given the following post, respond as if you're commenting on Reddit:
human
In Radiation Sickness, how does the latent stage - when patient looks and feels generally healthy even though the body is dying - work?

Why does that happen? Their body is dying, so what's the deal with suddenly feeling better. Is it similar to how your body goes into shock to keep you from feeling pain?
gpt
Cells use their DNA as templates (via RNA) to make enzymes and other proteins. Acute radiation poisoning smashes the DNA to such an extent that it is not functional. Transcription can't happen, as not enough DNA remains intact for it to do so.

During the "dead man walking" phase of radiation poisoning, the cells are able to use the existing proteins, but they can't make anything new. As old proteins degrade, they aren't being replaced. This causes a breakdown in homeostasis. Meanwhile, however, the longer-term tissues of the body continue to work as normal, they don't need to do much transcription. This includes the brain and muscles (including the heart), the liver, the kidneys and the pancreas.

Cells can't divide (they can't even try, the DNA to do so is bust) so epithelial cells in the skin and  alimentary  canal cannot maintain their tissues. This is a longer term problem, and one our patient won't live long enough to worry about.

The epithelial domain includes the entire gut, so sufferers have extremely acute GI issues. It also includes the skin, so it tends to "slough off" as it isn't being replaced as normal but the processes pushing cells outwards don't cease.

This opens the possibility of using artificial means to keep a person alive.  Hisashi Ouchi was kept alive for 83 days after an extremely intense radiation exposure which would have otherwise killed him in a few days. It's best not to research him very much: Nerves remain entirely functional, and he'd have been in unimaginable agony throughout.