Mom was right (did you ever question it?) More than 50% of body heat is lost through the top of the head. The N-Ferno Cold Series buttons you up tight with 2-layer protection against long winter days and cold winter nights. N-Ferno Warming Products include winter liners and other head wear designed to keep workers warm and comfortable. Weve 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.