"The Patagonia R1 Pullover is the layer that earns its place between a base and a shell when the pace stays high and the temperature stays low. The open-grid construction and HeiQ Pure anti-odor treatment work together to handle the full range of a multi-day push: venting hard during the climb and staying fresh when laundry is days away. What Our Gearhead® Experts Are Saying:""I wear this as my first layer over a base on cold climbing days because the Polartec Power Grid fabric moves heat away from my skin fast enough that I never have to stop and strip it off."""