I rode in the brisk 18* weater to work this morning and all i have to say is avoid it at all cost lol I layered up and parts of my body were so cold they hurt, and I had a problem with freezing on the inside of my windscreen from the condensation of me breating, I dont know how to fix that but im sure someone has a way

Nate goes to King Gyros for his winter protection:
http://thanasis.com/baklavaL.jpg

Man, I like to ride. but I if its not at least 50, Im not riding. You people are crazy.... haha. I've been caught out colder, like down to 35, but never gone out intentionally with it being that cold to start off. I ride to get enjoyment out of it, and if its that cold, I can't enjoy it. I can ride snowmobiles in -20, but not a bike.

For the solution, you can get a heated visor. I wouldn't bother fitting one to your existing helmet, just buy a snowmobile helmet. It will have dual panes on the visor which reduces fog. that combined with a heated visor, you'd be all set.

If you have issues with just fogging, you can look into a dual pane visor. It will reduce the fogging by quite a bit. the only downside is they are not as clear as a single pane visor.

Or just be a puss like me and not go out in it...:)