Wool is an amazing material created by nature for both summer and winter use.
To a larger extent than any other fibres, wool has the capacity to absorb and contain moisture. In fact, wool is capable of absorbing 40% of its own weight without feeling wet (cotton absorbs 7%). Therefore, wool is an ideal material as the inner layer of clothes.
Joha manufactures both 100% wool clothes and wool combined with other materials. The website also contains details about the different combinations.