The short answer
Supply the gear the site requires, walk the crew around before anybody starts, name one person in charge, and keep water on site. Ten minutes at the start prevents most of what goes wrong, and almost none of it is complicated.
The ten minute start
Before anyone picks up a tool, walk the whole crew around the site. Show them the work, the boundaries, where the tools and material live, and anything to stay away from.
Say the hazards out loud even when they seem obvious. The soft spot in the floor, the wasp nest, the neighbor's fence, the drop at the back. People who just arrived do not know your site.
Then say who is in charge and how to reach you if you are not staying.
Gear you supply
Workers bring their own boots and gloves. If the site needs anything beyond that, it is on you to have it there.
- Hard hats anywhere something can fall.
- Eye protection for cutting, grinding, or demo.
- Vests near traffic or moving equipment.
- Fall protection above about six feet, anchored to something real.
- A stocked first aid kit that somebody can find without asking.
The four that cause the injuries
In this kind of work the same four keep showing up. Falls from height, being struck by something, getting caught in or between equipment, and electricity.
If your job involves a ladder, a trench, a lift, or a wall with wiring in it, that is the part of the day to slow down and plan out loud.
Heat is a safety issue, not a comfort one
Have drinking water on site, and enough of it. Give short shade breaks through the afternoon rather than one long one.
Know the signs and say them to the crew: dizziness, headache, cramps, or somebody who stops sweating. Confusion or fainting is a 911 call.
Do not put people on equipment they do not know
A worker who has never run a skid steer, a lift, or a big saw should not learn on your job. Ask what they have actually operated before you hand anything over.
A person saying they have not used one before is doing you a favor. Treat it that way, or you will get answers that are not true.
Let people stop you
Tell the crew at the start that they can say stop if something looks wrong, and mean it. The cost of listening is a few minutes. The cost of a crew that has learned not to speak up is an injury nobody saw coming.
If somebody refuses work they believe is dangerous, fix the condition or change the plan. Firing them for it is illegal and it is a complaint with a short deadline.
If somebody is hurt
Care first, then write down what happened while it is fresh, then call your insurance agent the same day. See the guide on what happens if someone gets hurt on your property for the full order.
This guide is general information, not legal, tax, or insurance advice. Rules differ by state and by situation, so talk to your own professional before you rely on it.