Sleep Disorders

Sleep is a complex phenomenon influencing essential physiological processes such as physical restoration, learning and memory, neurocognitive performance, and immune system functioning. In physiological studies lowering the minimum body temperature has been suggested to positively affect slow wave sleep and sleep quality. In this view, this chapter is focused on the effects of cryostimulation on sleep. Whole-body cryostimulation or partial-body cryostimulation improved subjective sleep quality in both healthy subjects and athletes and in patients affected by several diseases such as long coronavirus disease 2019 (COVID-19), major depression, and active rheumatic polymyalgia. Furthermore, cryotherapy had beneficial effects on restless legs syndrome and could theoretically improve respiratory disorders such as apneas or hypopneas. However, in most of the studies, sleep has been assessed by questionnaires and sleep quality in terms of movements during sleep has been evaluated in healthy subjects, but there is a lack of studies that have carefully examined changes in sleep stages with polysomnography and the effect of cryotherapy on sleep breathing disorders. New, more accurate studies regarding sleep and its pathologies are needed to explore the possible effect of cryotherapy on sleep.