Sometime in the early 80s I did a marine fire fighting course. Mock-up of a ship, two decks and two compartments on each deck. A small wood fire in one of the lower compartments. Using breathing apparatus and fireman’s suit we had to go in and search for a ‘body’. Couldn’t see a hand in front of your face and the deck was too hot to stand still on. We all ended up with minor burns even with all the kit. Without the BA sets you would have zero chance of getting out.