Core gaps on the fiber structure of thermal yarn ensures that the cloth is both warmer and lighter. It provides continuity of comfort in cold weather by preserving body temperature. Wide fiber surface eases evaporation and ensures that humidity is removed from the skin and fabric. Sweated off humidity causes the cloth to get wet. If wetness is not removed fast, it causes to feel cold. Thermal fabric avoids body's discomfort due to humidity by fast transfer of wetness.