Caring for nonwork-related injuries

I am doing off-and-on temp work in an occupational health clinic at a manufacturing plant. I've been noticing that we get several employees in the clinic each day that come in for treatment of injuries that didn't happen at work. For instance, today, I saw a girl that had two scraped knees from a trip and fall accident at home. She had bandaged them at home but came in to the clinic for someone to look at them, clean them, put antibiotic ointment on them, and redress them (using Telfa bandages, gauze, and ace wraps). From what she told me, she'd been to the clinic several days in a row already. The scrapes did not appear infected and were healing well. Another guy came in to have his poison ivy looked at. He'd been hiking over the weekend and fell in to a bunch of it. He'd been coming in to the clinic for Calamine, antibiotic ointment, bandaids, Telfa dressings, and ace wraps. He was planning to come back every day to have it looked at, cleaned, redressed, etc. Another guy came in for shoulder pain from a baseball injury. He'd seen his doctor and had negative xrays. But he was in our clinic for ice packs and cold packs.

So this is my dilemma....I am worried about my liability when taking care of nonwork-related injuries. The supervisor has no problem treating these folks, but I am uneasy about it. I even feel uncomfortable with employees that come in just to have a routine BP check. Some are borderline, and I tell them to see their doctor but some tell me they have no doctor. The supervisor says we do these services as a courtesy for employees and no one has sued them yet. But this does not seem right to me. Not only does it seem that the clinic is spending oodles of money for supplies for these types of injuries, but our time is also spent helping these folks when we could be moving on to the next person who doeshave a work-related injury.
We are also dispensing alot of OTC pills for headaches, stomachaches, and colds, and we don't have a standing order for that. There isn't a doctor at the clinic at any time, but there is one off-site.

What to do.....what to do......does anyone have any thoughts about this?