Jamieson, Fausset and Brown on Daniel 3:21

21. coats ... hosen ... hats--Herodotus [1.195] says that the Babylonian costume consisted of three parts: (1) wide, long pantaloons; (2) a woollen shirt; (3) an outer mantle with a girdle round it. So these are specified [Gesenius], "their pantaloons, inner tunics (hosen, or stockings, are not commonly worn in the East), and outer mantles." Their being cast in so hurriedly, with all their garments on, enhanced the miracle in that not even the smell of fire passed on their clothes, though of delicate, inflammable material.