I think if you walked into your local branch of NatWest just to pay some checks in, even if it was a very cold day, you would be hearing alarm bells ringing within a few seconds, and would probably be admiring the pattern of the banks carpet with a sharp pain in your neck within the next few minutes. Likewise, i wouldn't like to try walking around Heathrow airport wearing one. Boarding a plane would become quite an adventure i think. Common sense says "Don't wear one", but i think for people like Peter Beardsley they should be mandatory.