How Warm Is Polartec Fleece?

How Warm Is Polartec Fleece? Available in a lightweight, midweight and heavyweight fleece, each Polartec® Classic series fabric provides warmth, comfort and breathability. Polartec® 100 weight fabrics are the lightest fleece in the series, and are an excellent choice for a warm first layer. Is Polartec fleece warm? Available in a lightweight, midweight and heavyweight