Man of Honour
If you are in an emergency then you aren't going to faff around with looking someone's details up you need to have something on the person - necklace/bracelet etc - because people will act in time critical situations and not wait for some crap NHS computer to spend 5 minutes booting up to then hang at retrieving some information from some poorly designed database that runs on shoddy servers. You don't wait that 5 minutes because when someone pitches up in that kind of situation you don't have 5 minutes.
This isn't about emergencies though. This is about research that benefits everyone.