The Layering system is a system that protects people who are involved in SAR operations or do recreational activities, such as hiking, in harsh conditions. There are at most five layers to this system, the Shell layer, Insulation Layer, Clothing Layer, Wicking Layer, and the Underneath layer. The Shell layer is almost always a wind resistant waterproof material that is lightweight and that material is some kind of synthetic material. The Insulation layer is a wool or fleece material that keeps the body warm. There is a lot of dead air space in wool, which keeps one’s body warm. The Clothing layer is simply everyday clothing or clothing that is designed for comfort and to let air escape. The wicking layer keeps sweat from making contact with someone’s skin so they can stay warm and dry. The last layer is the underneath layer, which wicks away moisture so one can stay warm and dry, like the wicking layer. Depending on the weather, the wicking layer may not be needed for SAR operations and outdoor recreation.