Emergency signage should be clear, concise and to the point.
Here is a stellar example, the Fire Evacuation Plan for a hotel near Seattle-Tacoma International Airport. Only the top third of the sign has anything to do with fire evacuation; the rest of the plan is devoted to:
Safety and security
Guest room security
Safe deposit boxes
Reporting [suspicious activity]
Check out times
And the ever popular Hotel Laws of the state of Washington.