So, it suffocates and burns you, very cool...but...you can walk out?
Sounds to me like there is nothing forcing them to stay in it, so they can walk out, cease taking damage, and not suffocate.
It'd work amazingly with something like hold perosn.
Quote of the [insert timeframe here]: (Week? Perhaps! Year? Also maybe.)
"Those who have learned to walk on the threshold of the unknown worlds...may then with the fair white wings of Imagination hope to soar further into the unexplored amidst which we live."
-Augusta Ada Lovelace