The optimum room temperature in living spaces is usually between 20 and 22°C. It should be a bit cooler for sleeping, around 17 to 20°C. What steps should you consider taking if previous measures you consistently implemented result in you still feeling tired and exhausted, even after a good night's sleep? Perhaps the air in the room is too dry, and your sleep at night is disturbed. In addition to the temperature, air humidity is a decisive factor for restful sleep. A healthy humidity range is between a minimum of 40 and a maximum of 60 per cent relative humidity. As the airways do not dry out so quickly within this range, sleep quality improves over the long term.