Underdressing can be observed in Britain on most weekend nights. It isn't that the revellers are careless of their clothes; just not wearing enough of them. During this year's inclemency, police in Newcastle felt the need to recommend coats in low temperatures.
Lack of cloakroom facilities are often blamed, but sociologists trace it to the rise of the foreign holiday and the incongruous transfer of balmy Spanish promenading to more bracing Blighty.
Historians recall the Ancient Britons' penchant for fighting naked. Anthropologists argue it is about breaking taboos. Whatever, that famous pick-up line, "Get your coat, you've pulled," is long redundant.
Once, in Bolton, I remember seeing a blonde girl in very little, passing a middle-aged man hunched into his anorak, hood up against the rain and cold. It was like that haiku, the one about how marvellous it would be to see a butterfly in the snow.