The N-Ferno Extreme Series doesn't give a rat's rear end how bad the Ice Age wants to freeze your hot-blooded heart. It offers 3-layer, noggin lovin', heart warmin' performance to keep you comfy when Old Lady Nature is bringing her worst. N-Ferno Warming Products include winter liners and other head wear designed to keep workers warm and comfortable. We've got versions for cool, cold, and extreme conditions with hi-tech fabrics and superior features for reliable warmth from ear-to-ear. In fact, most liners have pockets next to the ears to hold warming packs.