It can be entertaining to contemplate survival scenarios sometimes. Let's see if we can make it interesting.
You are out with a friend on a longer day hike, have been hiking for about five hours on a trail in a park that's fairly remote and no cell service. Say something in the subalpine - rocks, granitic sand, pine trees, a few manzanitas and the occasional patch of grass.
Your friend while taking a picture takes a header off the trail into a rock. He loses consciousness. Comes to a few minutes after you get to him. His head hurts, his leg hurts, there's some blood on his leg. He's not quite oriented but he's being insistent on going the rest of the way.
You're in steep terrain, he has a Camelbak with water, snacks and windbreaker. You have the ten essentials and the same - water and food, and whatever else you take on trips of this sort.
It's three hours before sundown, and you haven't seen anyone for about two hours because most people visiting this park don't hike more than 2-3 miles. You're about eight miles out - you'd planned to bag the peak you've been hiking to, and a little slower than anticipated, but you're both usually okay going back in the dark. It's probably going to approach the low 30s at night - it's been in the low 70s all day. If you walk about a quarter mile back down the trail, there's a small stream to get water. You're down to a bag of trail mix. The area you are in is on flight paths for major airlines, but rarely sees any lower flying aircraft. Budget cuts mean there won't be a ranger on the trails til the weekend, since they only patrol when it's very busy and it's the middle of the week - you're out on a day off. Probably not going to see help for a while.
What's the plan?
How does the plan change when you are on a week long backpacking trip, carrying the gear you usually carry, and the scenario is more or less the same?