Very good question. I was actually describing what was my typical SAR rig, which I did not usually carry on a pleasure trip.

Actually, what is the most critical component of all is skill and experience with the problem. My most recent and significant FA situation involved a heat exhaustion situation on Anacapa Island (not exactly convenient to an ER, and like many National Parks these days, there was no ranger or other NPS people present. Fortunately there was a physician in the group and we were able to stabilize our patient (cooling water both interior and exterior) and get her down a 157 step staircase to our vessel. Fortunately, we had enough water and I had a bit of rope to provide a belay of sorts down the staircase.

I am a rusty, retired EMT and the physician, also retired, was a neurological pediatrician. Not the optimum choices for this situation but we got the job done satisfactorily. To a degree, you can predict situations, but you can never be sure what circumstances will arise.

In terms of gear, you will be well on your way with some sort of sterile dressing, wrapping of some kind (bandannas, duct tape), items that can morph into splint-like objects, mild pain relievers (for personal use), band aids and other very basic stuff. It is good to know CPR but in a backwoods setting, other than simple near drowning, your victim is probably going to die.

The ability to summon outside assistance may be the most critical item of all, since rapid transport is often the key to success.