Factual error: In the scene at O'Hara airport the paramedics meetup with a TSA officer. The TSA officer has a gun as a part of his uniform. TSA officers do not carry firearms. In addition, the CBP officer in the scene does not have on a proper CBP uniform. The CBP officer uniform has rank epaulets and officer has no epaulets, and the CBP uniform doesn't have a bar tie clip and the gun belt buckle is brass not stainless metal. (00:42:00)
Other mistake: Captain Casey has Lieutenant pins on his uniform instead of Captain pins. (00:31:00)
No Such Thing as Bad Luck - S7-E18
Character mistake: At the formal awards ceremony for Cruz the Police officers and Cruz are in dress uniform with their covers on. Serveride joins them on stage in uniform without his cover on and salutes Cruz. Serveride should have known to have on his cover for the ceremony. (00:58:00)
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 ★