Are you overlooking this one key factor in your hunt for a good mattress? Sleep experts say it's the key to a good night's rest

Breathability is important in a mattress. Take it from me, a product writer and reviewer with years of experience testing out mattresses and all things sleep-related.

I’ve tested some of the best mattresses on the market, and plenty of not-so-good options. Through this process of testing and research, I can tell you the breathability of your mattress will have a huge impact on the quality of your sleep.

I'm here to explain all, but you don’t just have to take it from me. I’ve also recruited multiple industry insiders and sleep experts to find out exactly why breathability is so important in a mattress.

Why is breathability important in a mattress?

First up, what do I mean by mattress breathability? Well, breathability is all about having airflow through your mattress. Some mattress fibres and fillings are better than others at allowing air to penetrate through the mattress.

Why is this important? I asked Dr Maja Schaedel, clinical psychologist and co-founder and director of The Good Sleep Clinic, which helps to treat sleep difficulties, Chris Tattersall, sleep expert and managing director at mattress brand Woolroom, and Adam Black, co-founder of mattress brand Button & Sprung, to help me explain.

Why is breathability important in a mattress?

‘Breathability in your mattress is vital if you want to create a restful, healthy sleep environment,’ says Chris Tattersall of Woolroom. ‘It’s important that air can circulate easily as you sleep, to allow moisture to be wicked away and keep you cool'.

Saying cool at night – or at least sleeping on a mattress that enables you to maintain a stable body temperature – is an important factor in getting a decent night’s sleep.

‘One of the biggest issues we have in maintaining sleep is in regulating our temperature during the night,’ explains Dr Maja Schaedel. ‘Our bodies can heat up during the night which then leads our brains to think that we need to wake up, either because it interprets the rise in body temperature as a sign of it being daytime or because it thinks it is a feature of our sympathetic nervous system – the fight or flight response when we sense threat or danger. Either way, it is very difficult to sleep when we are too hot.’

And a better night's sleep isn't the only reason mattress breathability is vital.

'Breathability also helps prevent the build-up of bacteria that thrive in a humid environment, a common issue with mattresses made from synthetic materials that trap in heat and moisture', continues Chris Tattersall.

So there we go, a breathable mattress will help stop you from overheating at night, which in turn will improve the quality of your sleep. What's more, if a mattress has air flowing through it, it’s also more likely to prevent the build-up of bacteria. I’d call that a win-win.

What type of mattress is the most breathable?

The construction of the mattress and the materials used to fill it are the key ingredients to making a mattress breathable (or not). These two elements should work together to promote airflow through your mattress.

Generally speaking, natural fibres are considered the most breathable fibres for a mattress. Cotton, wool, bamboo, silk, and even coconut coir, are all breathable and great at helping our bodies regulate our temperature throughout the night. Combine these with an open coil or pocket spring mattress construction and you have all of the ingredients of a breathable mattress.

‘Natural fibres, such as wool, will allow air to circulate easily, to draw moisture away from your body and prevent a build-up of heat due to the pockets of air within the fibres', says Chris Tattersall.

‘I would say pocket-spring mattresses with calico cotton pockets are the most breathable choice,’ Chris continues. ‘The different layers of material and metal springs offer more space for the air to flow through'.

‘The only truly breathable mattress is one made from natural materials,’ says Adam Black of Button & Sprung. ‘Only natural materials allow air to circulate, releasing heat or keeping warmth where it is needed, responding to your body temperature and keeping you comfortable all night'.

Amy Lockwood, Ideal Home's Sleep Editor, can confirm the breathability of a mattress made from natural materials. As someone previously prone to overheating in bed, she swears by the Hypnos Pillow Top Select mattress a pocket-spring mattress which is packed full of natural materials.

'I used to think I was just a hot sleeper' says Amy, 'I would regularly wake in the night because I was overheating and throw off the covers to cool down. But that all changed when I reviewed the Hypnos Pillow Top Select mattress and switched from a memory foam mattress to a pocket-spring mattress filled with wool, cotton, and natural plant fibres. I now realise it was the memory foam's lack of breathability causing me to overheat. On my natural mattress, my body temperature stays steady throughout the night, which means a much deeper and more restful sleep'.

What type of mattress lacks breathability?

‘Mattresses made from synthetic materials such as polyester, PU or memory foam lack the breathable, temperature-regulating properties that are essential for high-quality sleep,’ says Chris from Woolroom.

‘For example, memory foam is designed to mould to your shape using your body heat and pressure, but the fibres absorb this heat and give it no escape route, therefore increasing the risk of overheating and interrupted sleep'.

‘Mattresses with natural fillings such as cotton, horse or cattle hair, hemp and wool will breathe significantly better than polyester fibre, polyurethane (PU) foam and memory foam, as the fibres are more permeable,’ continues Chris. ‘This allows heat and sweat to pass through the mattress without becoming trapped and creating a hot, clammy sleeping environment.’

‘Think of mattresses like gym wear,’ agrees Adam from Button & Sprung. ‘A synthetic top is manufactured for maximum workout performance to make you sweat and work hard. A cotton T-shirt is breathable and allows for heat to circulate and keep you cooler.’

However, if you have your heart set on a memory foam mattress, all is not lost. Many mattress manufacturers specialising in foam mattresses and hybrid mattresses have worked hard to create airflow through their synthetic foams.

For instance, the Simba Hybrid Original mattress uses open-cell memory foam that allows for better airflow than standard memory foam and the brand then infuses this foam with graphite which offers improved temperature regulation. The Simba Hybrid Pro mattress takes things even further by incorporating a layer of wool into the mix to improve airflow even more.

Can you make an existing mattress more breathable?

Learning about mattress breathability is all well and good if you're in the market for a new mattress, but what if your mattress is otherwise sound aside from a breathability issue?

Rest assured, there are a few ways to make a mattress more breathable. The easiest solution is to add one of the best cooling mattress toppers to your bed.

‘Adding a breathable layer on top of your mattress, such as a wool mattress topper, will significantly improve the air circulation and temperature regulation of your sleeping environment,’ advises Chris from Woolroom.

As someone who has tested a lot of mattress toppers for my job, the one I opt for is the Woolroom Deluxe Mattress Topper. And Ideal Home's Rachael agreed in her Woolroom Deluxe Mattress Topper review.

Opting for the best duvet your budget allows (ideally with a wool filling), and bed linen made from natural materials can also help add breathability to your bed. But it's adding a breathable mattress topper between your body and your mattress that will really make the difference if you're struggling with overheating at night.