Hair suffering in the winter??

Has anyone else experienced this? My hair has grown alot regardless, but I'm having alot of shedding in these last few weeks. I think it's because I've gone down to once a week washings since it's so cold. After I was sick on Christmas, I went down to once a week because I got sick from washing my hair too often and then going out. (I know really dumb to do up North!) I was wondering, does anyone decrease their washings or up anything else during this time?

I decrease washing a little also because it's freezing here!  I would love to wash and go like I did in the summer but that's impossible for me because I'd be sick all the time.  I know people say you can only get sick from germs but I have to differ because even in the summer if I wash my hair and fall asleep in front of the fan or something I wake up w/a scratchy throat.

I do up the moisturizing in the winter months, especially on my ends and I try to protect them more.  I'll use a more heavy moisturizer like shea butter or my regular moisturizer w/castor oil over it to seal it in.