Having had an ambulance ride a couple of years ago I learned the benefit of carrying a sheet of paper in my wallet and pack, identifying myself, an emergency contact, my doctor, allergies to any medications, the medications I am currently taking. Each hospital station from the emergency room on that information like that allowed them to get to the problem quickly and avoid additional ones. The only difficulty I had was that each station wanted to keep the sheet of paper rather than make a copy and return the original. Had I been unconscious only the first station would have benefited.
A policeman friend has since told me that they are trained to look at cell phone databases searching for emergency contacts. Someone invented the concept of listing these with the letters ICE in front of the name. ICE = In Case of Emergency. Most people just list the names and the emergency people can't tell your wife from your pharmacist.
Hope this saves someone some time when seconds count.