Yes, it's January. Yes, it is very, very cold outside. And yes, these people are wearing no trousers.
Commuters in London were yesterday treated the bizarre sight of hundreds of fellow Tube travellers wrapped up warm in jackets, scarves, hats and mittens - and nothing on their bare, pale legs.
Women clad in skimpy underwear, and some men in even skimpier underwear (though most wore boxers) crowded the Tube in London - and the underground networks in New York and Mexico City - to the bemusement of their fellow passengers.Enlarge Enlarge Enlarge
The stunt - entitled 'The 9th Annual No-pants On The Subway Day' - was organised by a group called Improv Everywhere. The group claims its mission to to cause 'scenes of chaos and joy in public places'.
Unfortunately, they failed, as most commuters - despite some lingering looks - appeared to take the no-pants people in stride.
In London, most commuters studiously avoided eye contact with anyone who was not wearing pants - making life on the Tube business as usual.
'It looks chilly,' was the only observation to be made by Dawn Young, a pants-wearing passenger in New York waiting on the platform alongside several no-pants people.Enlarge Enlarge
'It's the first time I've seen it,' said Gintas Norvila, another New Yorker waiting on the subway platform. 'It looks very interesting,' he added - before burying his nose in his book once more.
It's clear that you have to do a lot more than take your pants off to get any attention on the London or New York subway.
The lack of reaction from blasé commuters did not dampen the enthusiasm of the no-pants people, however.
'It's a place to meet people that's not your traditional bar scene,' said Brady Kirchberg, 26, taking part in his third no-pants ride.Enlarge Enlarge
The event started in 2002 with just seven people.
It is not the only mass event organised by Improv Everywhere.
The group also organises a 'Slo-Mo Home Depot', in which scores of 'agents' pretended to shop at the American home-improvement store and then froze in place.