A New York-based comedic prank collective known for causing public chaos and joy has set up an unauthorised pop-up spa on the NQR platform of the 34th Street subway station in Manhattan.

The New York underground subway system can reach sweltering temperatures of 95°F (35°C) due, in part, to the heat generated by air conditioning units that only cool the interior of the subway cars.

Thus Charlie Todd, the founder of the prank initiative called Improv Everywhere, invited a dozen actors to stage a spa at the station for one hour. Dressed in towels, the cast made inconspicuous magnets to cover the “St” part of the station’s name, 34 St, to read 34 Spa. Decorating the pop-up spa was easy as the existing brown wooden benches already resembled sauna seating. Rocks were added to the layout along with a bucket of water and a ladle. The ‘steamroom’ consisted of a teak platform surrounded by four people with spray bottles of water, providing water mist for subway riders for anyone who wanted to cool down.

Lemon and mint-infused water was on offer for onlookers, in addition to hot stone massage – provided by an actor with no training at all.

The 1995 art installation on this platform – REACH: New York by Christopher Janney – allows passengers to create music by waving their hands in front of sensors. The music the installation provides contains wind chimes and bird noises, similar to the relaxing music often heard at a spa.

As big believers in ‘organised fun’ the group has carried out more than 100 ‘missions’ featuring tens of thousands of ‘undercover agents’ (performers). The group’s website sums it up: “Our missions are a fun source of entertainment for the participants, those who happen to see us live and those who watch our videos. We’re out to prove that a prank doesn’t have to involve humiliation or embarrassment; it can simply be about making someone laugh, smile, or stop to notice the world around them.”

Todd founded the movement in 2001 when he and his friends pretended he was the musician Ben Folds. He spent three hours in a bar as ‘Ben Folds,’ signing autographs, posing for photos and enjoying complimentary drinks. As a comedian and an actor, this experience provided the foundation for his idea to stage his own creative pranks in public places.