So that's what these are called! I love these things! I've actually heard/read one: The room was draped in gloom and vines. (Courtesy of Brandon Sanderson and Firefight, which I would highly recommend to anyone looking for a new trilogy)
AAACTUALLY the opposite of office would be onice instead of onfire. The opposite of off is on and the opposite of ice is fire so it's like a double negative XD