Text 999

The emergencySMS service lets deaf, hard of hearing and speech-impaired people in the UK send an SMS text message to the UK 999 service where it will be passed to the police, ambulance, fire rescue, or coastguard.
Simply by sending an SMS message to 999 you can call for help and the emergency services will be able to reply to you.

You will need to register your mobile phone before using the emergencySMS service.
To register using SMS text messages you must:
Send the word 'register' in an SMS message to 999
You will then receive SMS messages about the service
When you have read these SMS messages reply by sending 'yes' in an SMS message to 999
You will receive a SMS message telling you that your mobile phone is registered or if there is a problem with your registration

More details at http://www.emergencysms.org.uk/

Be responsible: only use 999 service if:
Life is at risk;
Crime/trouble is happening now;
Someone is injured or threatened;
Person committing crime is near;
There is a fire or people trapped;
You need an ambulance urgently;
Someone is in trouble, or missing, at sea,
Someone is in trouble on the cliffs or on the shoreline