I spent one memorable night in a gathering storm where the temperature hovered right around freezing. They humidity was right at 100% and we received alternating rain and snow all night long. Wetness was everywhere, despite a good bivy sack and a Goretex jacket. It was survivable, but it was not a whole lot of fun. Fortunately we were sheltered from the wind, which is a huge factor in hypothermia. Otherwise there could have been another ending to the tale.