Some snow-sports helmets—Giro Seam for example—are usable on the worst winter days. Look for something with adjustable vents, ear protection pads, and a visor, which are "all good for cold riding," says Contrell. But the Giro Reverb, a true bike helmet, is a better choice for most commuters. It has minimal venting and a simple design. You fit a hat or balaclava undernear, or use Giro's removable cap-style cotton visor to block fleeting winter sun or road spray.