HEATTECH Extra Warm fabric with Heat of Absorption and Heat Retention technology. Approximately 1.5 times warmer than our regular "HEATTECH". *Based on CLO values, which indicate the thermal insulation of clothing. *Recommended for temperatures of -5℃〜15℃. This is a guide when worn in combination with other clothing. Individual perceptions may vary. *Comparison with 2024 "HEATTECH" Extra Warm.