>What do you mean, it burns?

Discomfort. But I can't seem to find a source on what percentage is necessary. It might be higher than the suffocation percentage.

You mean, the gas? Dry ice, yes, because it is cold, but the gas? (This is the first time I heard that and I find it hard to imagine.)

I think Dylan's referring to the way elevated CO2 stings your eyes, nose, throat. Lungs too if it gets that far. It's weird sensation, and it definitely feels "hot" in a way. Asphyxiation by CO2 is quite unpleasant.

Ah, I see. That makes sense. Thanks for the clarification.

When you come into direct contact with something that cold, it causes a sensation that feels very nearly identical to being burned.