What makes you fall asleep? The main cause is your body clock, a time-keeper inside your body. But how to control and use your body clock? Scientists suggested having a shower before bed. Jumping into the shower around an hour before bed could mean you sleep better.

A warm shower helps you relax, and then after it warms you up, your core（核心）body temperature drops. This encourages you to fall asleep more quickly and sleep more soundly.

A study in 2019 said that a water temperature of 40℃ to 42. 4℃ produces the best-quality（最优质的）sleep. After people lie down, most of them take about 20 minutes to fall asleep. However, if you have a shower one to two hours before going to bed, you will fall asleep 10 minutes earlier.

Core body temperature drops naturally before you sleep, then drops further during the night. It rises again as you wake up. It is thought that taking a warm shower will speed up the drop in temperature before bed, as it brings blood to the surface of the body, and then the heat is given off.