Three main types of helmets are currently used in the United States. The "leatherhead" is just that--constructed almost entirely of leather. The leather's resistance to heat actually rivals that of modern composites. The large brim that dips down in back is designed to keep hose water dripping off of the ceiling out of the face. The leatherheads are used in fighting regular fires.Tradition vs Progress: The Art of the American Fire Helmet
The second type is the structural helmet, a more streamlined version of the leatherhead, constructed of thermoplastics or composites. These helmets are used for structural collapses and extrications. Goggles, instead of a face shield, often sit on the front of the helmet.
The last type is the European-style helmet, which looks like a cross between a motorcycle helmet and something from Star Wars. The design is purportedly much more comfortable and practical. But, as one firefighter put it, "I've been involved with fire departments in four states...and in seven years have seen a grand total of two [European-style] helmets... these guys were... universally afraid of being mocked for wearing something new, different or 'unfashionable.'"
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.