If you're serious about hiking/climbing you should never be in a position where you would need an apple watch to save you. You should always let people know where you are going, what you are planning to do, and when you plan to be back or at least back in contact otherwise they should call a rescue team. If you're solo climbing and your apple watch is what you're relying on in case of emergency you probably have far bigger issues to worry about
That being said, it does seem like it could be useful for the elderly in some scenarios