Can a weighted blanket really stop a heatwave ruining sleep?

Cooler weather is here for a few days, but with experts saying there may be another heatwave this week, it’s worth investing in something that makes it easier to sleep.

‘Our core body temperature slowly drops by a degree or two at the end of the day and during the first part of the sleep cycle, which encourages us to doze off and helps us sleep well,’ explains Dr Ari Manuel, a respiratory, sleep and ventilation consultant at Liverpool University Hospitals NHS Foundation Trust and Spire Healthcare.

‘Very hot weather, however, can interfere with this natural process, keeping our core temperature warmer than it should be, which is one of the reasons it can be harder to fall and stay asleep,’ he says.

But can cooling products help? We asked Dr Manuel and Nerina Ramlakhan, a physiologist and sleep therapist based in London, to assess a selection. We then rated them…

Cooler weather is here for a few days, but with experts saying there may be another heatwave this week, it’s worth investing in something that makes it easier to sleep

Weighted blanket Cooling Weighted Blanket, £69,

Claim: This 5kg weighted blanket is crafted with a ‘HydroCool material’ — a lightweight, man-made fabric designed to wick sweat away from the surface of the skin and cause it to evaporate. The maker says this blanket ‘keeps you at a comfortable temperature throughout the night’ to ‘induce restorative sleep’.

Expert verdict: ‘Weighted blankets are popular with people who sleep poorly, and those with anxiety and restless legs,’ says Dr Manuel. ‘The theory is that the evenly distributed weight of the blanket exerts a gentle but firm pressure on the body — similar to a massage or hug — which is thought to release the feel-good hormone oxytocin, cause lower heart rate and blood pressure, and bring on a sense of calm.

‘If you rely on a weighted blanket for comfort but find your usual one too hot and heavy during the heatwave, then this lightweight, moisture-wicking version could be a good option. Restless sleepers might find that a weighted blanket can help stop them moving around in the heat. But they are not everyone’s cup of tea.’

Nerina Ramlakhan adds: ‘Many of my clients find a weighted blanket helpful. The ideal weight is no more than 10 per cent of your body weight, and this 5kg version can fit into that category.’

8/10 Cooling Weighted Blanket Cooling Weighted Blanket

Chilly pillow 

Silentnight Cool Touch Pillow, £22.99,

Claim: This hollowfibre pillow has a pressure-activated cooling gel pad which absorbs heat and ‘helps to prevent overheating throughout the night’, says the maker.

Expert verdict: ‘When it comes to regulating your core body temperature, a significant amount of heat can be lost through your head and face, as they are areas of the body that we tend to leave uncovered,’ says Dr Manuel.

‘But while pressing your head on to a cool, gel-covered pillow might feel soothing, it’s unlikely to help physically cool you down. In fact, if the gel pad is cold enough to cause constriction of the blood vessels, it could slow your body’s natural cooling processes by limiting circulation at the surface of the skin, which would make you retain heat instead.’ 


Hydro topper 

ChiliSleep Ooler Sleep System Half King, £399.50,

Claim: This cooling, hydro-powered sleep system ‘actively manages the body’s temperature to help deliver deep sleep’.

A bit like underfloor heating or cooling for your bed, the electrical bedside unit pumps water into pipes that run through a padded mattress topper.

You can adjust the temperature of the water (between 13c and 46c) and the speed of the pump via an app on your phone and set a timer to allow the temperature to drop or rise overnight.

A four-week study of 75 customers reported that they were 36 per cent less likely to wake up because of discomfort during the night, and 40 per cent less likely to have trouble falling back to sleep.

Expert verdict: ‘Lying on a cool mattress topper won’t reduce your core temperature — but this could be useful if you like the sensation of lying on a cool surface and find it easier to fall asleep in a cooler environment,’ says Dr Manuel.

‘But you would have to be careful with the settings, as you could be left awake and chilly in the small hours if you don’t get the timer and/or heat adjustments right, as temperatures fall overnight.

‘People with a reasonable degree of tech know-how may enjoy using this and find it soothing.’

Nerina Ramlakhan adds: ‘It’s an expensive gadget that won’t suit everyone. I’m not keen that it works with an app, which encourages phone use in the bedroom. The artificial light may affect your body clock and disturb sleep.’


Cooling body wash

Elemis Cool-Down Body Wash, £30 for 200ml,

Elemis Cool-Down Body Wash

Elemis Cool-Down Body Wash

Claim: Designed to create a cooling sensation on the skin, this is ‘perfect for ending your day on a fresh note’. It’s formulated with cooling menthol, eucalyptus and magnesium.

Expert verdict: ‘Menthol and eucalyptus oils can provide a “cooling” sensation,’ says Nerina Ramlakhan. ‘Magnesium is also widely used as a bath soak for sore muscles and has been shown to be important in regulating sleep.

‘Although these ingredients may only be present in small amounts, treating yourself to a soothing wind-down at the end of a hot day is a great way to psychologically prepare for a better night’s sleep.’

Dr Manuel adds: ‘It’s tempting to take a cold shower before bed when you’re feeling hot and bothered, but you shouldn’t.

‘Cold water will make your capillaries constrict, and your body will naturally retain heat rather than lose it. A tepid shower can be a good way to relax and cool off, though — and menthol may help soothe the nasal cavities. So if the minty smell works for you, a product like this could help you feel cool and fresh.’


Breezy nightie

Become Anti-Flush Night Dress, from £31.46,

Claim: The maker says the fabric is ‘treated with two innovative coatings’ and woven with ‘a flat, cross-knitted thread to transfer heat and promote cooling’.

Expert verdict: ‘You might think sleeping naked is the best way to stay cool in this heat, but a nightie or pyjamas in a thin, lightweight fabric will actually help to wick away sweat from the skin and keep you dry,’ says Dr Manuel.

‘This fabric is designed to keep body temperature stable, but any natural fibre — such as cotton or linen — would also do a good job.’

Nerina Ramlakhan says: ‘Look for loose, seam-free and elastic-free sleepwear, like this, as it’s less likely to bunch up or cling.’


Timed fan

MeacoFan 650 Air Circulator, £87.99,

MeacoFan 650 Air Circulator

MeacoFan 650 Air Circulator

Claim: This ‘quiet fan’ has a timer switch so it turns itself off during the night, making sure you don’t wake up cold. Its eco-mode lets the fan regulate itself depending on the room temperature.

Expert verdict: ‘A fan can feel cooling on the skin as it encourages sweat to evaporate, but it won’t reduce your core temperature,’ says Dr Manuel. 

‘However, some people find circulating air soothing, so a bedroom fan could help you feel calmer and sleep better.

‘The timer here is useful as temperatures tend to drop overnight, so programming the fan to stop for a few hours after you’ve fallen asleep will hopefully mean you won’t wake up feeling chilly.’

Nerina Ramlakhan adds: ‘I find the white noise of a fan helps soothe me to sleep, so this quiet model wouldn’t be my first choice. A small, inexpensive travel fan would work well, too.’


Move the mattress

‘Hot air will always rise inside your home, so sleeping downstairs or simply moving your mattress from a high bed frame to the floor should offer a significant temperature difference — and hopefully a more restful night,’ says sleep physiologist Dr Guy Meadows, co-founder of Sleep School. His other tips include:

Change position: ‘If you usually sleep on your front or back, try sleeping on your side for a change. Lying on your side exposes a larger area of the body to the air, allowing heat to escape more efficiently.’

Keep furniture cool: The NHS advises that you keep windows shut and curtains closed on the sunny side of your home during the day. Sun streaming through windows will heat not just the air in your house, but the floors, furniture and counter tops, too — all of which have a high capacity to store and then radiate heat long into the evening.

Create a cross-breeze: Once the sun goes down, swap the warm air in your bedroom for cool outside air. An hour or two before bedtime, open your bedroom window, and then a window on the opposite side and opposite end of the house.

Leaving the doors between the two rooms wide open (and closing the doors of any rooms you’re not using), place a fan, pointing out of the window, in the room on the opposite side of the house.

When you turn the fan on it should create a low pressure system, forcing warm air out and boosting the intake of cool air through your bedroom window.