2083691 Mountain Hardwear Women's Microchill Shirt The Microchill Shirt is perfect for warm-up laps at the crag, long approaches on misty mountain mornings, or cruising around town when the weather calls for something warm and cozy. Made with soft recycled fleece, designed for easy layering over your favorite base, under your go-to shell, or worn as a light outer layer all on its own, it's a versatile stylized piece you might just keep forever.