The hazard
A small fire can get out of control fast, and smoke can make it hard to see or breathe before you ever see flames. A fire can start from something simple, like a pile of scrap, a leaking gas can, oily rags or a heater too close to something that burns. Preventing a fire is always safer than fighting one.
The action
On construction sites, access to all firefighting equipment must be maintained at all times. Know where the nearest extinguisher is before you start, and make sure nothing is stacked in front of it. Never block exits or the paths to them, even for a few minutes. (29 CFR 1926.150(a)(2))
ASK THE CREW
Where are the nearest extinguishers and exits from where you are working today?
From the talk: Fire prevention. Read it in full, free, with the questions and the sign-in sheet.