I don't feel any responsibility to them, either, beyond that of simple decency: if I have more than I need, and they look like they might seriously need it, I'll share. This rarely extends farther than a map, some granola bars, or an offer to use my filter to refill a couple of canteens.

We were camped about 6 miles from a trailhead once, many years ago, when a group of 8 or 10 dayhikers showed up, around dusk, asking if the trailhead was just over the next hill. (It wasn't.) After explaining that the trailhead they wanted was behind them, not in front of them (and that they should have known they went the wrong way when they stepped off the blacktop), and that it was about 6 miles away, we did ask if they'd like to spend the night with us. We couldn't spare any tent space or sleeping bags, but we did have a few space blankets and some fleece jackets, and could have fixed them a light meal (that was back when we all carried "emergency" food.) When they declined, we filled their water bottles and gave them a map and a spare flashlight (a cheapie, which might have even lasted all the way back.) Then we went to bed, and figured that the worst outcome was that the gene pool would get a bit deeper.