Cold getting under your skin?
or better yet, getting into your home. You should check the chalking around all your windows to ensure they are still in tact. If not, get some chalking from Home Depot and ensure all your windows are properly sealed this will help with drafty areas.
Another good area to check is under the window trims, gently remove the trims to check for large gaps between the window and your walls. If you find large gags fill them up using a foam spray.