It is a long shot to call this a sport, but it definitely is extreme. People who do extreme ironing go to a remote location and iron clothes! Really. They call themselves 'ironists', and get a thrill from taking their ironing board, unplugged iron and some of their wrinkly clothes to some extreme places and photograph themselves doing it.
Such places that they have reached include extreme altitude, underwater, hanging from cliffs, and on top of vehicles.
Please do the ironing, but don't try these extremes at home.