Basic First Aid Kits

Since I work in construction, I always have a relatively new first aid kit in my truck just incase of an on the job accident which we have never had in 25 years now. There are some everyday items you can use for first aid for instance I always have a couple bottles of Sterile saline solution for my contacts that can be used to flush out the eyes. I use I think it's lubriderm moisturizer on my hands because of concrete work. The calcium in the cement is hard on skin and it helps with that and could be used for sunburn and perhaps mild burns. I'd defer to Buzz's recommendation on that.

So Can anybody suggest everyday things that could substitute for first aid in an emergency situation?