Always carry passport and EHIC card whereever you go. Security may ask you for ID especially if you are entering at night. Recent car thefts has increased security, Offenders coaught , but learning a lesson do not leave windows that are easy accesable open at night and ensure you secure property when away even at swimming pool..
If medical treatment requiried have passport and EHIC card with you always. a reminder as it creates problems without it
http://www.ehic.org
David