Whether it's an intermediate layer or underwear, wool and fleece, the children can never have enough. We have fleece jackets, two split fleece suits, wool jumpers and wool underwear for active children. The middle layer is an insulating layer that is neither innermost against the skin nor outermost. The weather can change quickly, but if you have the right middle layer, junior can easily take it off or on to regulate heat and ventilation. Wool underwear can be used all year round, as wool has the ability to retain heat 4 times as much as cotton, but is still cool when it's hot.