As an absolute minimum, and assuming adequate clothing and a plentiful supply of water:
AMK Heatsheet
Mini-Bic lighter x 2
Pre-made tinder
Photon III
SAK or small Multitool
Whistle
Mirror
15' paracord
If the kids are responsible enough to go on a campout then they should be required to be on their honor to carry at least this much at all times.
Actually, there needs to be an exception to that... When they are swimming or bathing... Or in some kind of emergency...
Now you might think that this is obvious, but it SHOULD be spelled out, and SPECIFICALLY mentioned that it is allowed...
Why, you might ask???
For a VERY important reason...
You are asking them to 'be on their honor' to do something ALLWAYS, but knowing that they are NOT expected to do it ALWAYS...
This leads people(not just kids) to think that their 'honor' is only a 'sometimes' thing, and that it has unwritten exceptions...
This should never be the case...
That is one of the reasons that I think is is VERY counterproductive to have laws on the book, that everyone ignores, and that are almost(or completely) unenforced...
It leads to a disrespect for the law, both by the people that break them, and by everyone that watches them being broken every day...
Honor is one of the most important things that Scouting teaches, and it should not be undermined for no(or little) reason...
Honor is not taught in the schools anymore, and most of the time, not at home either...
I sometimes find myself slipping...
It is easy to keep your word, when it is important, if you have any honor at all, but, it is when it is UNIMPORTANT, that honor shows most of all...