Paramedics and other first responders recommend to mark one (or more) of your mobile phone contact entries as “ICE”. ICE is short for In Case of Emergency and tells them who to call when you're in an accident. A good idea.
Security experts on the other hand recommend to make sure your phone is properly locked so nobody can access your data when you lose it. An excellent idea as well.
So what to do? Well, most modern smart phones allow you set up a custom wallpaper for the lock screen. So why not create your own image which tells first responders who to call without a need to unlock the phone?
This might help to get your phone back should you ever lose it and some honest soul finds it, too.
The image shows what my iPhone lock screen now looks like1).