A new bedtime ritual might deliver a better night’s sleep: Take a bath 90 minutes before you hit the sack.

Not only is the timing of the bath important, so is the temperature — new research shows 104 to 109 degrees is ideal.

To establish their findings, University of Texas researchers reviewed more than 5,300 relevant studies. They extracted data about bathing before bedtime, also known as water-based passive body heating.

Bathing at the optimal time and temperature, they found, can hasten the onset of sleep by an average of 10 minutes. It can also help optimize the body’s circadian clock, a mechanism within the brain that drives 24-hour patterns of sleep and wakefulness. The findings were published in the journal Sleep Medicine Reviews.

While much of the science of body heating and its effect on improved sleep has been established, less is known about the optimal timing of core body temperatures.

Warm showers or baths stimulate the body’s internal thermometer, circulating more blood from the body’s core to the hands and feet. That helps to optimize the body’s natural circadian process, which drives many biological processes, including sleep. Optimal body temperature increases the chances of falling asleep quickly and getting high-quality sleep.

Next, the researchers want to use the findings to develop a bed with thermal stimulation technology. Beds with separate temperature zones and adjustable heat would allow each person to customize their sleep experience throughout the night.

So, before you head off to bed, step into a warm bath or shower. It could be your shortcut to dreamland.