Mobile phone operators could be required to allow users to text the emergency services as a result of new proposals from Ofcom.
The regulator says a small trial of the scheme has been running in the UK for a year, and has attracted 14,500 registered users.
It has been used predominantly by deaf and speech-impaired people; but also by others including hill walkers and those working in dangerous situations with a poor mobile phone signal.
During the trial, the service was used by people suffering from heart attacks and strokes and going through. An average of one text per day required attendance by the emergency services.
Users are encouraged to indicate what service they need, what the problem is and where they are in their text; but the emergency services can get an approximate location for the sender.
The proposal to require mobile operators to provide an emergency text service comes in response to European regulations requiring equal access to emergency services for disabled people by the end of May 2011.
The emergency SMS service would be an add-on to the existing 999 and 18000 services that are available in the UK. The text message service would be connected to 999 through the Text Relay 18000 service.
A relay assistant sends an SMS message to a 999 advisor, and their reply is sent back as an SMS message. However, the service is only available to those who preregister, in order to avoid prank calls.