bluesign-Approved Materials with Thermoregulating ActiveIce for Sunny Days The ActiveIce Spectrum Sun Long Sleeve Tee is built with thermoregulating ActiveIce™ technology and bluesign® approved materials, perfect for keeping body temperature in check while hiking, backpacking, climbing, or setting up camp. This tee is built with an ultra-comfortable, breathable, and quick-drying polyester blend treated with our proprietary ActiveIce™ technology. ActiveIce™ reacts to your body's rising temperature by cooling down your core, keeping you in the sweet spot longer while pushing the tempo or working hard. The chafe-free design, built-in stretch, and UPF 50+ are welcome essentials for long days spent under the sun, delivering comfort and maximum range of motion on reachy boulder problems or tight slot canyon squeezes. Purpose-built for staying cool while spending long days in the mountains under the sun, the ActiveIce Spectrum Sun T-Shirt is a warm-weather staple for every outdoor enthusiast.