The hazard
What the people nearby do in the first few minutes after an injury can make a big difference. On a jobsite, help can be farther away than you think, and nobody wants to be hunting for gloves or a phone signal while a coworker is bleeding. A little planning now means everyone knows their part before anything happens.
The action
Everyone should know where the first aid kit is, whether it is in the trailer, the truck or the shop. On construction jobs, the kit must be in a weatherproof container and checked before it goes out to each job and at least weekly, so used items get replaced. If you use the last of something, tell your foreman. (29 CFR 1926.50(d)(2))
ASK THE CREW
Where are the first aid kits and eyewash stations on this site, and who keeps them stocked?