...some good advice I once got from a police air wing pilot with extensive experience in searching for missing a/c..was to carry a portable ELT on your person on any flight that will take you outside a populated area.
The reasoning for it was simple. He has personally been involved in search efforts that ended in finding victims that perished literally hours prior to being rescued.
The accident a/c was each equipped with an ELT that failed to work upon impact. The victims sustained non life threatening injuries which affected their mobility in some way and resulted in death due to extended exposure to the elements.
I have since made a habit of carrying an ELT on every flight in addition to those handy nik naks such as a leatherman & torch.