"The Patagonia R1 Air Jacket is built for the moments when the effort stays high and the temperature stays low: the long skintrack, the sustained ridge scramble, the pre-dawn run where stopping to adjust layers costs time. The jacquard fleece construction creates an open, lofted structure that moves sweat off the skin and releases heat at pace, so the jacket stays comfortable across a wide output range without the clammy buildup that kills a midlayer's usefulness. What Our Gearhead® Experts Are Saying:""I wear this on the skintrack and keep it on through the first few turns because the hollow-core yarns dump heat fast enough that I never have to stop and strip a layer."""