Fierce Burning When Oxygen Enters a Closed Room
Puzzle 2 of Patterns in Nature Pack
Question is: Fierce Burning When Oxygen Enters a Closed Room
and the answer is: BACKDRAFT
Word Meaning:
BACKDRAFT — (American spelling, firefighting) Sudden, dangerous recombustion that occurs when there is a rapid reintroduction of oxygen to an enclosed space containing a fire.
Definitions from Wiktionary.