When it comes to great sleep and the correct room temperature, it’s all a bit ‘Goldilocks’ – not too hot, not too cold, it’s got to be just right. But what IS just right? What is the best temperature to sleep in?
Well, according to our research it’s cooler than most people think; in fact the Sleep Council recommends that the optimum temperature for sleeping is between 16C and 18C (60-65°F), with slightly higher temperatures for younger children and elderly adults.
But it’s not that simple. Because a bedroom that’s too cold could negatively impact your sleep as much as one that’s too hot: sleeping in a cold bedroom of about 12°C (53°F) will make it difficult to relax and drop off, while sleeping in a room temperature of over 24°C (71°F) is likely to cause restlessness. Confused? Understanding the biology behind all this might help. It’s all about how your body prepares for sleep, and what your body gets up to during sleep.
A key part of the biological sleep process is the general cooling of your core body temperature, especially in the Deep Sleep phase; one theory is that this helps you conserve energy during sleep when your body is busy at work repairing and restoring itself; it can also be a signal from your internal body clock, your circadian rhythm, that it’s time to sleep.
So what happens? Your body lowers its temperature at night the same way it does during the day; your skin temperature sends signals to the rest of the body to either circulate blood or emit sweat, helping you to either warm up or cool down. So far so good. But if your body is too warm as you enter the Deep Sleep phase, you’ll get a double whammy of heat-lowering sweat - the one generated because you’re too hot, and the one generated by the body’s normal sleep process. As a result, it’s likely you’ll wake up sweaty and uncomfortable before you finish your Deep Sleep cycle, and before you even begin your REM sleep stage. In addition, this drop in the body’s core temperature at night is key to levels of melatonin, a hormone that helps regulate sleep-wake cycles and encourages sleep by inhibiting signals that promote wakefulness.
Disrupted sleep cycles
So sleeping in a cold bedroom is better for sleep, because overheating interrupts not just one but two crucial sleep phases; Deep Sleep and REM sleep.
A lot goes on in the Deep Sleep and REM stages of our sleep cycle. Without a healthy dose of both you’ll wake up feeling unrefreshed and drowsy, with reduced alertness and attention, plus you’ll have trouble learning and remembering things as well as experiencing cravings for high-calorie food. Insufficient deep sleep may decrease your immune response and leave you more vulnerable to infection; reduce the elimination of potentially harmful waste products from the brain. As a result, disruptions to deep sleep may also drive advancement of neurological conditions such as Alzheimer’s and Parkinson’s disease. Additionally, sleep deprivation is associated with hormonal changes that drive our appetites, and going short on deep sleep especially is believed to contribute to the development of type 2 diabetes and heart disease.
How to maintain the ideal temperature for sleeping
A warm bath before bed: Heating your body at least an hour before bedtime may help induce slow-wave or Deep sleep, and its following phase, REM sleep. The warmth from the bath draws heat to your hands and feet which then dissipates. The process allows you to cool down to a comfortable temperature for sleeping.
To sock, or not to sock? Your feet are a key temperature indicator to your brain, so in the winter, warming your feet by wearing bed socks can make the rest of your body overheat later in the night. But wearing socks to bed in the summer is a different story, helping regulate body temperature through a process known as thermoregulation; this is the body's ability to maintain its core temperature within an optimal range despite external temperature changes.
Here’s how it works: Your brain constantly monitors your body temperature, triggering physiological responses to either conserve or dissipate heat. But socks warm the feet and trigger vasodilation, where blood vessels in the skin widen and increase blood flow to the skin's surface. This enhanced circulation facilitates the release of excess body heat, reducing the body's core temperature.
Choose a breathable duvet. Look out for duvets with fillers that are designed to maintain body heat but also support air circulation; this allows excess warm air to escape, taking any damp or moisture with it. Simba Hybrid® duvets are a great example; our Summer Hybrid® Duvet, the Hybrid® Duvet and 3-in-1 Duvet use an advanced combination of ‘cool-touch’ technology and airy, down-like filler in different tog levels, to suit your preferred level of warmth.
Discover ‘cool-touch’ technology. Our Stratos® ‘cool-touch’ technology is designed to provide extra heat diffusion and soothing tangible freshness on one side throughout the night, even using pillowcases and duvet covers, and it’s a feature on all Simba duvets and pillows. The range includes the award-winning Hybrid® Pillow and Hybrid® Firm Pillow, as well as our budget-friendly Stratos® Pillow and our ingenious Body Pillow.
Change your mattress. Even if you use a mattress protector your mattress will become clogged with natural body oils and sweat after a few years which will undermine its breathability; the independent Sleep Foundation recommends changing your mattress every six to eight years.
