A warm bath, of around 40 and 43 degrees Celsius, for as little as 10 minutes can significantly improve overall sleep efficiency. In other words, a warm bath leads to more time spent in actual sleep rather than turning or tossing and trying to fall asleep, compared to usual sleep without taking bath. When scheduled one to two hours before bedtime, a warm bath can also hasten the speed of falling asleep by about 36%. Why does the warm bath or shower help? There is science behind it. Our body temperature is not constant during 24 hours. It is higher in the morning and evening, and it is lowest during night-time sleep. The body temperature needs to drop to initiate good sleep. When we take a warm bath or shower, the body brings large amount of blood flow to the surface, especially hands and feet. This blood flow brings the heat from the core to the surface and rejects the heat to the environment and causes a drop in body temperature. Therefore, if you take a warm bath or shower at the right biological time – one to two hours before bedtime – it will aid your natural circadian process and improve your sleep.