Your in or near the capital aren't you?
When they up the alert level I am concerned but try not to let it make me paranoid. However, I do do things that I believe, rightly or wrongly, might give me some added protection. For example, when travelling on national rail trains I always get in the last carriage in the belief that a bomb would have to be placed towards the front of the train to have the desired effect. Also, if I have to go a few stops on the underground, I opt rather to take the bus which might put 5 or 10 minutes on the journey - but I have only done that when they have stationed armed police at every underground entrance.