Sleep is important for both your short-term and your long-term health. Your mood, memory, and energy levels are better when you’ve slept well. Sleep also decreases the risk of many serious health issues, including heart attacks, strokes, and diabetes.
Many people would like to get better sleep, but find that it’s sometimes challenging to fall asleep. In the US, more than 1 in 7 adults have trouble falling asleep every night or on most nights.
If you regularly get into bed and then find it tough to fall asleep, there’s a simple technique that may help. Research has shown that taking a hot shower or bath late in the evening can help you to fall asleep faster.
How does taking a hot shower or bath improve sleep?
This technique works because it helps to align your body temperature with your natural circadian rhythm—the daily 24-hour rhythm that keeps you in sync with the sun. Every aspect of your body is affected by your circadian rhythm, from your brain activity to your metabolism to your body temperature. These all need to be aligned properly for you to fall asleep.
As you get closer to bedtime, your circadian rhythm triggers a natural drop in your body temperature. The change is not huge—only about a degree or two—but it’s important. This slight lowering of your body temperature is part of how your body gets prepared to shift into sleep mode.
When you take a hot shower or bath, this slightly raises your body temperature. The blood flow to your skin increases—this is why your skin tends to look a little pink when you’ve been immersed in hot water. After you get out of the shower or bath, the increased blood flow to your skin continues for a while, which helps to dissipate excess heat from your core and causes your body temperature to drop. This mimics the natural drop in body temperature that normally occurs as you approach bedtime.
The benefit to your sleep is not just theoretical. Research has shown that taking a hot shower or bath as part of your bedtime routine can help to improve sleep latency, meaning that it helps you to fall asleep faster.
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