I'm with teacher. The whole kit that we made up was to encourage the child to stay put, drink water, not get too hot or too cold, and to give them something to do while staying put including actively signally with their whistle, mirror, flashlight, etc.

I also have told our kids since they usually do outdoor stuff in a group that if they get lost, to take turns signalling while they wait in one spot.

Oh yeah, we also tell them to stay put on the trail unless it is dangerous to do so.