I have used these pants a few times on cold weather hikes and love them. The material is fairly stretchy for the weight and I really like the high waist with built-in belt. The side vents are fantastic for high exertion activity, particularly in stop-and-go situations, as you can open them up while moving for maximum breathability yet close them during stops to preserve heat. I run very hot and sweat a lot during hikes, especially when carrying weight, so the vents are perfect for me. I used them on a rainy day, and while the face fabric around the shins seemed to wet out a bit, no water penetrated to the inside. I am planning to take these with me to Mount Rainier this Spring.