The Ice line of Sparco Soft-touch Nomex Underwear utilizes Sparco’s unique X-Cool treatment. X-Cool is a chemical treatment applied to the fabric consisting of micro capsules that are freed as body temperature rises. These capsules move away from the heat source (in this case, your body), thus lowering the overall body temperature. A by-product of this treatment is a refreshing menthol fragrance that is released as the capsules move. Crew length protects up to mid-calf.