Lot of good advice above. What you're getting is several decades of advice on things often learned the hard way. Dressing in layers makes it much easier to stay warm and dry while also allowing you to shed a layer or 2 if you're hiking or it gets too bulky for shooting. Since you're hunting in a treestand, that will have its' own set of challenges. Are you in a climber, metal ladder treestand or a wood platform treestand?