The N-Ferno 6481 Lightweight Base Layer Pants are designed for comfortable warmth in mild to cold conditions. Made with lightweight and breathable stretch fabric, they are a great base layer bottom for keeping workers warm without overheating during strenuous activity. The 180g polyester-spandex performance material provides warmth without the constricting or bulky feel often found with heavyweight base layers. The fabric is smooth and stretchable for easily layering under work pants