Wool is a natural material that has been used for thousands of years, both in clothing and for sleeping.
Our body still reacts to external influences in the same way as it did in previous millennia: it sweats, it gets cold, it gets hot. Wool helps our sleeping comfort, it is a very good moisture and heat conductor (and regulator). In addition, it is an excellent thermal insulator.
It keeps you warm on cold winter evenings, yet it can release heat, keeping you cool in summer. Due to its breathability, it helps to avoid excessive sweating and the formation of unpleasant odors, and prevents the proliferation of bacteria and mites. It also has a beneficial effect on the environment. You don't have to worry about microplastic emissions that would harm nature.