The season for wearing jeans is in the woods is over: actually it should never really start.  The saying "Cotton Kills" holds truth in the backcountry. Cotton  has absolutley no insulating properties once it gets wet. Avoid what my friend Roger is doing here as he explores the trails and pumps water at the  Bald Mountain State Recreation Area (The rustic cabin is availabe for rent from the Michigan DNR) and switch to one of the many excellent synthetics available at stores such as MooseJaw or REI, or online at http://www.railriders.com/. Railriders - a personal favorite-  offers a great "winter pants" for adults.  Bottom line: when hiking in cold weather always wear a good wicking base layer. Fleece can be another layer - and holds in heat even when wet - but the exterior needs to be wind proof and at the least water resistant.  Keep your head covered to prevent heat loss and don't forget quaility socks such as Smart Wool. Lastly-- nutrious food and plenty of hydration is a must to keep your internal furnace fueled. Go hiking! The snowy trails are waiting.