A Real Shot in the Arm - S8-E2
Continuity mistake: When Sylvie and her ex hometown friend are having milkshakes, both milkshakes keeps switching back and forth between full with whipped cream and a cherry (when Sylvie is in view) and partially full with melted whipped cream and no cherry visible (when her friend is in view). (00:20:00)
Answer: Internet sources give many reasons why firefighters do this, but in regards to your question, it's probably because opening walls and ceilings creates better ventilation which allows heat and smoke to escape, giving firefighters better visibility and lowering the temperature.
raywest ★