Polar fleece fabric is soft, light, fast drying, easy to wash, and still keeps out the cold when wet. All things being equal, it’s twice as cold resistant as Merino wool and four times as cold resistant as cotton.Lightweight polar fleece is easy to move around, does not sweat, and is a good way to keep the fabric dry while wearing, thus maintaining body temperature.On the environmental front, polar fleece is a synthetic fiber that can be made in part from recycled plastic bottles.It also produces the same carbon footprint as wool, but is much more durable.