So, if you (or your significant other or loved one) were brought in on 9/11/01 as one of the WTC survivors, with burns so severe that your clothing was gone and you'd passed out from the pain and shock, your identity was unknown, and you were dying, you'd want the doctors to stand around and wait for you to be identified and for your next of kin or guardian to give permission before they stuffed you in a hyperbaric chamber to try to save your life. Or would you want them to stuff you in the chamber first to try to save your life and ask stupid questions later? I very much think the latter is the case here.
Hyperbaric chambers as immediate treatment for burns were an "investigative medical device" on 9/11/01. And no, it's not like an iron lung - after the treatment time was up, you are removed from the chamber.
I could give hypothetical scenarios to the contrary point of view but I won't. Its really pointless. As I said this is a tough call. I acknowledge your point of view and your arguments hold water. But IMO no one should be subjected to experimental medical practices w/o some form of consent.
On a side note I know something about burns. And if a loved one of mine were brought in on 9/11 with the injuries you are describing which I am presuming mean 3rd degree burns over most of the body, as painful as it would be for me... I hope I would have the courage to let them go. I know someone who was burned very badly in a fire but not as badly as you are describing. His life has been hell on earth since then.