So I've been told by a friend that misfolded proteins in prions are extremely resilient, to the tunes of needing ~900C/1800F to destroy. Indeed a quick google search seems to generally back up those numbers. I'm very confused.

My question is why? It's still a protein isn't it? "Normal" protein, eggs meats etc, denature at like 60-80C which we cook and eat. I can understand how specific structures of prions help against those. Then at the mid-100's things start charring and turning into carbon. It would seem to me like that process doesn't really care how the protein is structured; so long it's protein it should?

Failing that, it's still an organic compound isn't it? Like most it's still exothermic when it burns? Most organic things catch on fire below say 500C, and as far as I can tell if it has long carbon chains it basically can't be more stable than CO2/H2O. What sort of activation energies are we looking at that prions don't catch fire at 900C?

Suppose I have a prion-infected deer brain or something and throw it in a searing hot pan or even over (mid temp) open flame. Does it not cook/char/burn? How does that work?