To stay warm and comfortable in the woods at night you can do many things. If you can build a small fire and know how to control and direct the heat that is good but sometimes you cannot do this. For example if you are looking for something to keep you warm at night, first look for what is already there: an open shelter, a tree that fell in a way that shelters and is small enough to keep the body heat etcetera. You can also go the other way and dig a little bit under a log to make a small shelter and gather small branches and leaves to make a heat barrier. It is the trapped air which insulates and keeps the heat near you so even if the material is wet it can still work if you have a nylon or something like it around you. If you have a car than you can sleep in it but even there make the space smaller using a coat and papers crumpled up. If you want to move about and you don’t have a good coat or a blanket to wrap around you, you can panel your shirt with leaves which will create an air trap and keep your body heat from escaping. Wind is one of the best things if you want to cool yourself but avoid it if you need to conserve energy.