Here in the UK you can contact the emergency services by dialling either 999 or 112.
Calls to these numbers from both fixed and mobile phones are free, as are calls from payphones.
In some European countries (Sweden, Denmark and The Netherlands), the sole emergency number is 112 whilst other member states have adopted the same system as the UK and use the number 112 alongside their national emergency numbers.
All EU member states must ensure that emergency services are able to establish the location of the person calling the 112. The ability to locate the caller in case of an emergency may be of great significance in a situation where the person is unable to state his or her location, which can happen particularly when calling after a traffic incident on an unfamiliar road at home or abroad.
For more information about calling emergency numbers in Europe: http://www.eena.org/view/en/index.html