With temperatures around the country reaching the soaring heights of late summer, there are likely to be a few grouchy and tired Kiwis dotted around offices and schools.
When it's hot and sticky, it can be a bit of a challenge to fall asleep. Perhaps you have a particularly warm apartment, a west facing upstairs bedroom or a sleep partner who’s simply hot-blooded all year round.
If this sounds like you, don’t despair or decamp to the lawn tonight. There are ways to cool down on hot evenings, so you can get a good night’s sleep and wake refreshed and ready for tomorrow.
How body temperature affects sleep quality
On a normal day, your body temperature will start to dip slightly in the early evening, as part of the circadian rhythm. Think of this as your 24-hour internal body clock, which regulates when you sleep and wake. It’s controlled by cells in an area of your hypothalamus called the suprachiasmatic nucleus (SCN for short).
Daylight tells your SCN – via your eyes – that you should be awake, and stimulates the release of cortisol – a hormone that keeps your body temperature at its normal waking level (around 37°C).
When the sun goes down, your eyes tell the SCN that it’s time to sleep, causing your body to release melatonin, a hormone that makes you feel relaxed and sleepy, and lowers your core temperature. Once in bed, your temperature will keep going down during the first stages of sleep, and stay down for most of the night. It gradually returns to normal before you wake up. Being too hot interferes with these processes, particularly during the initial sleep stages, waking you up. Or you may struggle to fall asleep.
How to cool down and drift off
Here are our top eight hot tips for a cooler sleep, whenever it’s needed.
Invest in a fan
An electric fan can blow the stifling air out the window, through your house from the cool side to the hot side. Try aiming the fan at the window to blow out the balmy air, which will create a vacuum to pull cooler air back in. It may sound counterintuitive, but give it a go. If you’d love the effect of air conditioning without the bulky unit or desert-like lack of humidity, try instead directing your fan at your bed across a bowl filled with icy water.
Keep a cool head
Put your favourite pillow in a sealed Ziplock bag and pop it in the fridge or freezer for an hour before you head to bed. Or simply try this technique with a pillowcase in a breathable natural fibre. There are pure silk and linen pillowcase options specially designed to fit the versatile Go Pillow and Back Sleep Pillow. Both pillows are also made from open cell memory foam technology, which creates an airflow matrix to prevent heat build-up and keep you cool.
Get calm and collected
Emotions like anger, worry and frustration can make you feel overheated and create difficulty with getting to sleep. Cooling your thoughts can also help you relax and cool your body. It can help to prepare for bed by dimming the lights and switching off the TV and any devices. Apart from the blue light, scrolling social media or watching the late-night news is a recipe for filling your head with worries. Try some gentle yoga stretches, meditate or journal, and see what makes the most difference.
Wind down in good time
Exercise raises your body temperature. If you can stop exercising several hours before you go to bed, it will give your body plenty of time to cool down. Taking a gentle walk in the evening air can help to calm and clear your head though – just keep it slow and easy.
Hydrate inside and out
It’s a good idea – especially in summer – to drink plenty of water throughout the day. You may also want to keep water on your nightstand – although don’t drink too much before bed or you’ll be waking up for another reason. You could also try wetting a facecloth and placing it on your forehead, or misting yourself with a spray bottle containing cool water and a few drops of lavender essential oil (if you have some).
Avoiding alcohol may help too, as it can cause you to feel warmer.
Shut the sun out
This one is essential, especially for those of us in a west or north-facing bedroom. You could try closing your curtains as you leave for work in the morning, while opening the windows (if you can do it securely). This will allow air to circulate, but keep the sun from heating up the room during the day. You may want to consider temporarily changing your bedroom to a cooler spot in the house if you can. Downstairs is usually a little cooler than upstairs too.
Give yourself some space
If you’re sleeping in a room or a bed with other people and you’re constantly having broken sleep due to heat – consider temporarily sleeping alone if you can, or creating space to allow your body heat and theirs to dissipate. You may be able to achieve this by getting a bigger bed, but test with a break to make sure that heat is the cause of your sleepless nights.
Go au naturelle
When it comes to sleeping soundly in hot weather, natural fibres like linen and 100% cotton are your friends. Avoid synthetic microfibre sheets and polyester satin nightwear, which will trap heat and perspiration, opting instead for cool, lightweight cotton pyjamas and linen bedding.
In the meantime, we’ll look forward to the cooler nights that come with the crunch of autumn leaves – snuggling up with heaters, getting into cosy PJs pyjamas and wrapping ourselves in soft blankets.