As I understand the question, your emergency contact is someone who knows you and something about you, the more the better. This person would be an individual who knows you went hiking (or whatever) and should have returned. Ideally, they would be able to give a clear description of your route and plans.
I was suddenly the emergency contact for a close friend and colleague years ago,attending a significant national conference in Washington, DC. I was presiding at our seminar and all of a sudden my friend, in the back of the room, went into a full blown grand mal seizure. The first paramedic reaching the scene said, "Forgot his medicine, right?"
I was able to state, " I know this guy very well. This is not normal. There is no medicine." My friend couldn't communicate and I rode in the ambulance to the ER where I answered questions, etc., called his wife, etc. and hopefully provided insight and information. Quite a memorable experience.
Geezer in Chief