It might be worth mentioning that in at least one jurisdiction with which I am familiar (National Park Service) charges are brought against, and costs are recovered from, folks who do really silly things. This is only done in extreme, very clear situations, for the reasons that MH has mentioned.

The NPS is making it clear in their orientation for hikers in the Grand Canyon, a real hotbed for rescues, that they are not legally obligated to effect a rescue, and that they may be so busy that Mommy may not be immediately at your side to kiss it and make it well.