Select ski pants from The North Face feature their Chimney Venting™ system, for enhanced comfort when conditions warm up. These vents are strategically placed down the outside of the thigh, and feature a long zipper opening. This lets warm air traveling up from your boot to flow easily out of the pant, keeping your legs cool. This vent is also mesh backed to keep any snow from getting inside the pant, perfect for days when you might be warm from hiking in deep snow.