The Dynafit Men's Short Sleeve Trail 2. 0 Shirt can't adjust the ambient air temperature but will give its best effort to keep your hard working body cool and comfortable. Thermocool fabric manages moisture so sweat doesn't stick around, either on your body or in the shirt. Air mesh inserts increase airflow around your core to make 20 mile runs in August a little bit less awful. Silky against your skin, this high performing shirt works well for hiking, golfing, or playing disc with the dog or kids.