Emergency contact - how to set this?

[Bahamen]

I would like to set an emergency contact on my phone that would be accessible in the event of an emergency and my phone is locked. How can this be done? Currently it allows emergency calls from a locked phone, but what qualifies as an emergency call? Would it be numbers designated by the telco for emergency services e.g. police or ambulance hotlines?

 

[LightenSkies]

If I'm not mistaken its like calling 911 only. Depending on region you are from.