The ‘cotton only’ rule you need to survive the heatwave

As more sweltering nights loom, many people across parts of the UK will be preparing for yet another restless night. While fans and open windows often get the most attention, it seems what you wear to bed could have just as much impact on your nightime comfort.

It comes as the country experiences its third heatwave of the year, and second in as many weeks, with the Met Office forecasting soaring temperatures of around 30C. Research by YouGov found that two in three Brits have struggled to sleep, while almost half say they have lost at least three hours of sleep each night.

According to lingerie and nightwear brand Pour Moi, one of the biggest mistakes people make is sleeping in synthetic fabrics. It recommends swapping to coton pyjamas, which could help keep you cooler and more comfortable throughout the night.

Ellie Sheach, a nightwear buyer at Pour Moi, said: “During hot nights, it’s easier to feel sweatier than normal, and sleeping in synthetic materials can cause moisture to build up – which will only make this feel worse.”

She added: “If you’re not ready to ditch the pyjamas entirely, the most important switch you can make to keep yourself cool is choosing nightwear made of cotton. It’s breathable, moisture-wicking and gentle on the skin. Basically, everything your synthetic fabrics aren’t when temperatures rise.”

Ellie says cotton is particularly effective because it allows air to circulate around the body more easily than synthetic material. Such airflow helps reduce heat build-up and may lower the risk of heat rash and skin irritation during warm, humid nights.

Cotton is also naturally moisture-wicking, meaning it draws sweat away from the skin to help keep sleepers feeling drier as they rest. According to Pour Moi, this can make a noticeable difference on nights when temperatures remain high long after the sun has gone down.

Comfort is another factor. Loose-fitting cotton pyjamas are less likely to rub against the skin or leave marks, helping reduce irritation and making it easier to sleep uninterrupted.

Ellie added: “Whatever you choose to sleep in this summer, avoid anything too tight. A loose-fitting, breathable cotton set is the ideal solution. Your skin – and your mood the next morning – will thank you for it.”

The advice is also reflected in guidance from the Sleep Foundation, which recommends lightweight, breathable natural fabrics such as cotton to help regulate body temperature during hot weather. Combined with keeping bedrooms as cool as possible and staying hydrated, choosing the right sleepwear could make tonight’s heatwave a little easier to manage.