While Monteverdes cloud forests filter out the sun, its Costa Ricas simmering heat that eventually wears you down. Wrap yourself in this T-shirt for some skin-pampering relief. The lightest of our merino wool baselayer fabrics, Merino 1 Silkweight is made to keep you cool and comfortable in warm-to-hot conditions. Merino is breathable, regulates body temperature and stretches. It's wonderfully soft and naturally resists odor. Our fine merino wool is responsibly sourced from the grasslands of Patagonia. We slow wash it for softness and shrink resistance, without the use of chlorine, then blend it with 35% Capilene polyester (100% recycled) for durability, dry times and moisture transfer superior to that of 100% merino. The set-in sleeves and offset shoulder and side seams lie smoothly beneath pack straps and a self-fabric collar feels soft against skin. Machine wash cold; machine dry at low temperatures. Fabric is bluesign® approved.