At Hamburg Airport, there are a couple of those new Body Scanners tried. While the police websites rant and rave about them, more serious news sites have uncovered, that sadly, clothes prevent them to be functional.
So I guess you will have to walk through naked in order for them to work.
And even better: A science TV mag have made some tests - if you wrap a revolver in a steak, which is of body warmth, they don't show it.
One word: FAIL