Are you tossing and turning, hot and cold, waking throughout the night...Most of us have trouble getting a good nights sleep at some time throughout our life, especially during menopause and as we age. Lets start with one of the most critical factors for improving your sleep - temperature.
So, what exactly is the relationship between body temperature and sleep? Your circadian rhythm (internal body clock) regulates many functions of the body including heart rate, blood pressure, hormone release, and body temperature; all which act together to help you stay awake during the day, and sleep at night. However, in either hot or cold sleep environments our bodies struggle to reach the optimal body temperature for sleep which leads to restlessness, difficulty falling asleep and staying asleep.
For optimal sleep, your ideal room temperature should be between 18 – 22 degrees celcius( 64-72 degrees fahrenheit). Body temperature starts to fall as bedtime approaches, paving the way for a good night’s sleep. Maintaining your environment between 18 – 22 degrees can help facilitate this. Temperature settings lower or higher than what’s recommended could lead to restlessness and can also affect the quality of REM (rapid eye movement) sleep – the stage of sleep with the highest brain activity.
How do you achieve the ideal sleep environment? It can help to think of your bedroom as a cave—it should be quiet, cool, and dark for the best chance at getting enough rest. If you don’t have climate control to maintain your ideal room temperature, there are many other ways which you can keep cool.
Scientific studies have tested the sleep of both older and younger adults and found that wool helps keep the body in the "thermal comfort zone" most conducive to restful sleep.
When wearing Merino wool, older adults are falling asleep at least 10 minutes faster than when wearing other fibres, and younger adults are getting at least four minutes extra sleep in wool, than if wearing other fibres.
The latest study conducted by researchers at The University of Sydney, with support from The Woolmark Company, has found adults wearing wool fell asleep in just 12 minutes compared with 22 and 27 minutes for those wearing polyester or cotton.
The study found fabrics made from natural fibres allowed for higher rates of heat and moisture transfer and higher thermoregulation than those made from synthetic fibres.
“Wool regulates your body temperature far better, keeping you in what is known as 'the thermal comfort zone'. You therefore not only fall asleep quicker, sleep longer, but also have deeper, better quality sleep.”
The study also found that the lower humidity in the skin microclimate when wearing wool sleepwear promoted more restful sleep in comparison to polyester and cotton sleepwear.
“Our continuing research in sleepwear fabrics has shown benefits of sleeping in wool," explains researcher Associate Professor Chin Moi Chow, from The University of Sydney. “Maybe it is not a coincidence because wool regulates your body temperature far better, keeping you in what is known as 'the thermal comfort zone'. You therefore not only fall asleep quicker, sleep longer, but also have deeper, better quality sleep.”
An earlier study, also conducted by the University of Sydney and The Woolmark Company, which was published in the journal Nature and Science of Sleep (2016) researched the effects of fabric for sleepwear and bedding on sleep at ambient temperatures of 17°C and 22°C.
Seventeen healthy young adults underwent nine nights of polysomnography testing and found that the time it took to fall asleep was significantly shortened when sleeping in superfine Merino wool, with trends of increased total sleep time and sleep efficiency compared to cotton sleepwear. The group fell asleep four minutes faster on average when wearing Merino wool rather than cotton, taking 11 minutes instead of 15.
From pyjamas, blankets, doonas, mattress covers and pillows, wool aids in a better night’s sleep.
Here are some of our top tips:
- Natural fibres in sleepwear and bedding help you regulate your temperature, especially Merino wool.
- Close blinds/curtains during the day to block out heat from the sun
- Keep your bedroom door open, and open other windows in the house to allow air to circulate freely to cool the house.
- Cool off before bed. Try bringing your core body temperature down by taking a bath or a shower.
- Don’t vigorously exercise before bed. Exercise raises body temperature, and may take longer to cool down. Late night exercise is especially unhealthy for those suffering from insomnia.
- Keep a water spray bottle for misting, or keep a glass of cold water next to the bed.
- Use a fan to circulate air.