I bought one of those for my brother-in-law. He is a logger and works alone. He could easily be pinned by a log or his skidder. Unfortunately, I think he uses it intermittently.Everyone should get a personal locator beacon for going off trail. I use it for scuba diving in very remote spots. It's not that useful stuck in water for days but on land it's quite useful when lost.
The satellite gets pinged and the us coastguard will contact the authorities of whichever country you are lost in to find you.