There is no doubt that in cold and wet conditions it is very important that the clothing retains body heat and do not skip the moisture. Wool is one of the best materials for these conditions. Even got wet, it is still warm enough, does not let a lot of moisture to the body, worn long, and if the clothes are made from good quality raw materials, not too prickly.
Sheep's wool is the most popular type of wool, due to it being widely available and highly versatile. Very fine quality wool is used to make high-end fabrics for use in luxury garments likes suits, dresses, sweaters, and other apparel. Medium quality wool is used in the production of heavier sport coats, sweaters, and light blankets. Coarser wool is used for heavy blankets, topcoats and outerwear, and upholstery products.