Wool is a hygroscopic fiber; it absorbs moisture in vapor form. Tiny pores in the epicuticle make the fiber semi-permeable, allowing vapor to pass through to the heart of the fiber. Wool can easily absorb up to 30% of its weight in moisture without feeling damp or clammy. This capacity to absorb makes wool a “temperature regulator” because it can protect the body in both cold and warm conditions. Wool always absorbs moisture from the atmosphere of greater humidity and releases it to the drier environment as it creates a balance in moisture conditions. This characteristic makes wool a versatile all-season fabric. Wool wicks moisture away from the skin; thereby creating a layer of dry air next to the skin which, in turn, helps to hold in body heat. As wool absorbs atmospheric moisture, the hydrogen bond of water is broken and chemically reacts with molecules of the wool to generate heat. The wool hoodie is good protection against hypothermia… a condition that occurs when sudden drastic lowering of body temperature causes the body to lose heat faster than it can be produced. The same principle of moisture contact on the skin acts to protect against hot weather as well. The body cools itself naturally with the evaporation of perspiration. Wool expedites this process by absorbing perspiration and keeping the same dry air next to the skin.
This is why wool clothing is worn throughout the desert regions of the world where it’s hot during the day and cool at night
The flexibility of the wool fiber also makes it more durable. A wool fiber can be bent back on itself more than 20,000 times without breaking, compared to about 3,000 times for cotton and 2,000 times for silk. The natural elasticity of wool also makes woolen fabrics resistant to tearing. In addition, the outer skin of the wool fiber acts as a protective film, giving wool cloth improved resistance to abrasion.
Because wool contains moisture in each fiber, it resists flame without chemical treatment. Instead of burning freely when touched by flame, wool chars and stops burning when it is removed from the source of fire. Wool is self-extinguishing. It will not support combustion; this is why wool blankets are recommended for use in extinguishing small fires.
