One of the most overlooked (arguably) hazards for this time of year is frost. At least in the northern climate.
Strains and sprains contribute to many if not most claims on the worksite. frost on smooth surfaces can cause slipping and falls. Especially in the mornings when frost can be on most surfaces and workers can be the least attentive. They can be carrying in tools and equipment and are in a hurry to get set up and started. Slipping on ramps, floors, ladders, and other surfaces should be a concern.
So what can we do to protect the worker? Perhaps starting with a "Tool Box Talk" on the hazard. Take the time to assess the work zone before beginning to set up. Carry less tools material and equipment on the first trip from the truck to the site and assess the work zone.
If you have any other ideas I would love to hear your solutions. There are many hazards on the site, every one we can eliminate, can only be a benefit.