By Alexandra Thompson Senior Health Reporter For Mailonline
Published: 10:48 BST, 22 July 2019 | Updated: 10:49 BST, 22 July 2019
Rather than counting sheep, relaxing in a bubble bath before bed could combat insomnia.
Indulging in an evening bath or shower an hour-and-a-half before you turn in boosts the time spent asleep and the quality of shut eye, research suggests.
Experts said water temperature of 40-to-42.5°C (104-to-108.5°F) is 'ideal' and speeds up sleep's onset by up to 10 minutes.
Warm baths and showers redirect circulation to the hands and feet, which causes a drop in core body temperature, the researchers claim.
This triggers the body's internal clock into thinking it's time for sleep, with body temperature naturally reducing in the run up to bedtime.
Relaxing in a bubble bath an hour-and-a-half before bed could combat insomnia (stock)
The research was carried out by The University of Texas at Austin and led by Dr Shahab Haghayegh, of the department of biomedical engineering.
Insomnia affects up to 35 per cent of adults in the US to some extent, according to Sleep Education. In the UK, a third of adults claim to have insomnia, statistics show.
In the short term this can make sufferers feel fatigued. But over time, a lack of shut eye can lead to depression and even heart disease.
'Water-based passive body heating', such as warm shower or bath, is often recommended to combat insomnia, the researchers wrote in the journal Sleep Medicine Reviews.
However, how or why this occurs was relatively unclear.
The researchers therefore analysed 13 studies that investigated how a shower or bath affects sleep.
'When we looked through all known studies, we noticed significant disparities in terms of the approaches and findings.' Dr Haghayegh said.