Recent studies on sleep patterns in France suggest that the average sleep duration has fallen to 6 hours and 50 minutes per night, with many individuals reporting disturbed sleep, particularly when room temperatures remain too high. Researchers have identified a mechanism that could influence the bedtime routine of millions, without the need for medication. A room temperature of 18°C is said to favor the production of melatonin, a hormone that regulates sleep, and improve paradoxical sleep, with 108 minutes of paradoxical sleep recorded in cooler conditions compared to 85 minutes at 25°C. Paradoxical sleep, also known as rapid eye movement (REM) sleep, is a stage of sleep associated with dreaming and cognitive restoration. The 4-7-8 breathing technique, which involves inhaling for 4 seconds, holding one's breath for 7 seconds, and exhaling for 8 seconds, repeated 3 to 4 times after turning off the light, is reported to slow the heart rate and promote falling asleep. Lowering the heating in the evening and avoiding screens in the last hour before bedtime are recommended to support this sleep induction protocol. The critical period following the extinction of the bedside lamp appears to be around 19 seconds, during which the body can trigger the necessary physiological reflexes for sleep. Some specialists recommend gradually lowering the room temperature in the hours preceding bedtime to mimic the body's natural cooling process. The combination of a cool room and the 4-7-8 breathing technique is said to create optimal conditions for a rapid transition to sleep by simultaneously affecting body temperature and the nervous system. A scientific study has measured a noticeable difference in the quality of paradoxical sleep according to the temperature of the room, reinforcing the idea that cooler temperatures are not just a matter of comfort but a concrete physiological lever. These findings suggest that small environmental adjustments could significantly improve sleep quality for many individuals.