Call us crazy, but we just happen to think your headwear should consistently provide a beggars banquet of BTUs. So quit playing with matches and build a bonfire around your brain with the element busting energy of the N-Ferno Cool Series. All 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.