Which Materials Provide the Best Insulation When You're Cold?

Down

• Made of goose feathers, down provides insulating warmth in cold weather. When down is packed into a coat, for instance, air collects between clumps of fluffy feathers and is warmed by body heat. The result is a "warm pocket between your body and cold air outside," according to Canadian retailer Live Out There. For optimal warmth, look for a down coat with a breathable lining that allows excess moisture to escape while retaining body heat.

Polar Fleece

• Lightweight, breathable and free of animal products, polar fleece will keep you warm in cold weather. Made from polyester, there are several varieties of polar fleece, but they all insulate the body in the same way, through air pockets that capture warmth produced by the body. Polar fleece also maintains its ability to provide insulation after multiple washings, making it a good choice for long-term, frequent use. For comfort, polar fleece is also a breathable material.

Wool

• Just as wool keeps sheep warm, so it does people when turned into clothing. Wool is comfortable and breathable in both cold and warm weather, making it ideal for times when temps may change fast. In chilly climates, wool absorbs excess moisture, according to Sheep 101, but allows warm air to remain near the body for insulation. Wool is also a strong fiber and able to withstand rigorous wear and tear without sustaining damage.

Thinsulate

• Lightweight and non-bulky, Thinsulate is produced by the 3M company and used in boots, pants, coats and other garments. As with other insulating fabrics, Thinsulate keeps wearers warm by trapping air. The extra fine fibers in Thinsulate are able to trap large amounts of air in a relatively small space but allow moisture to escape, making it dry and toasty. Thinsulate is also breathable and can be machine-washed, unlike more delicate fabrics.