Natural Heating and Cooling
Wool often has the stereotype of only being good in the cold. You can credit all the wooly sweaters and scarves you wear in winter, but wool truly is a 4 season fiber.
Think of a sheep. When they get a bit chilly, they don’t head to the closet and grab another layer. When they get warm they don’t throw on a cotton t-shirt. They only get one shot at it and Mother Nature has given them the perfect clothing to keep them comfortable year round in all kinds of conditions.
Wool has a natural crimp to it that helps it trap more dead air than any other fiber. Dead air is a fantastic insulator and provides a great buffer against the cold.
Plus, wool fibers do such a good job of moving moisture away from the skin that even if the fabric is soaking wet the surface area of your skin will remain dry. Merino fibers and fabrics can absorb up to 30% of their dry weight before feeling wet. Most synthetics feel wet after they absorb less than 7%.
Wool has the ability to store moisture within the structure of the fiber. As your body warms up, the moisture stored within the fiber will begin to evaporate, cooling the air between your skin and the fabric. The warmer you get the more evaporation takes place and the larger the cooling effect