Just because the mercury has dropped, it doesn't mean you have to stop riding your ATV or UTV.
While you're likely in for a miserable day if you go out for a ride in your regular gear when you can see your breath or snow is on the ground, with proper planning and the weather-appropriate attire, you can extend your riding season as long as you'd like.
With some additional accessories, you can get away with wearing your regular ATV helmet. However, a helmet designed for cold weather is a smart option. To find a good one, we look to snowmobilers for winter riding inspiration. Snowmobilers are the kings of finding ways to stay warm in the bitter cold and if they use a helmet, you can bet it will keep your head and, in particular, your face, much better protected from the cold winter wind.
See the Winter Helmet Buyer’s Guide: http://www.atv.com/buyers-guide/2015-winter-helmets-buyers-guide-2370.html