Restorative sleep is a central requirement for health and quality of life. Sensible nightwear can make an important contribution to this. However, while sports clothing has been revolutionised during the last few decades through innovative fibre developments and functionally optimised design, almost nothing has happened in the area of nightwear. The company Dagsmejan located in St.Gallen has now designed and implemented a new type of nightwear in collaboration with material scientists (EMPA), textile designers (Lucerne University of Applied Sciences and Arts) and sleep researchers (Uni Stockholm), which optimally supports the physiological requirements of the sleeping body – in particular thermal regulation. Two innovations have made this possible: 1. The development of a delicate natural fibre based on beechwood with hydrophobic properties, which combines a pleasant feel with functional characteristics. 2. The invention of a special knitting process, with whose help sleep-optimised ventilation zones can be seamlessly integrated into the clothing.