The Hot Chillys Kids' La Montana Zip T-Neck might be very light and soft, but it is a powerhouse of warmth! Micro-denier polyester yarns are used to make it super warm without being thick and bulky. The Hot Chillys Kids' La Montana Zip T-Neck is brushed with an anti-pill finish on the face to keep it looking nice, and MTF Moisture Transfer Fibers make sure the fabric stays dry.