These versatile long johns feature an ultra-soft, midweight fabric utilizing our features ClimaSense Thermoregulation Technology that automatically adjusts to your body temperature. It does this be trapping air to maintain warmth when your body starts to cool down. When your aerobic activity increases and your skin temperature rises, the fabric allows moisture vapor to escape to maintain comfort. Whether skiing, mountaineering, fat biking, snowshoeing or winter running, Thermolator is functional performance at its best! The Kids Thermolator Performance Pants goes perfectly with the Kids Thermolator Top and other pieces from the Kids Thermolator collection.