Millions of Brits Who Sleep With Their Window Open at Night Warned…
With warmer evenings returning, millions of UK households are once again cracking open the bedroom window to cool down and drift off — but sleep and security experts are urging people to think twice before leaving windows open overnight.
Whether it’s for fresh air, white noise or temperature control, sleeping with your window open might be doing more harm than good — and in some cases, putting your safety and health at risk.
If you rely on an open window because you struggle to fall asleep, sleep experts at Roseway Labs, a compounding pharmacy specialising in natural sleep support, suggest turning to simple, science-backed foods instead. Their top recommendations: Pistachios, naturally packed with melatonin, magnesium, and healthy fats. Helps support muscle relaxation and deeper sleep. A small handful (about 1 ounce) is often enough before bed.
Also, warm milk. It contains both melatonin and tryptophan, which may promote natural relaxation. A cup of warm milk before bed has been a well-known sleep remedy for centuries.
Miriam Martinez Callejas, Superintendent Pharmacist and Founder of Roseway Labs:
“Melatonin is your body’s natural sleep hormone, released by the pineal gland when it gets dark. It helps you fall asleep, enhances REM sleep, and keeps your circadian rhythm in check. Adding melatonin-rich foods to your diet may help regulate your sleep cycle and improve the quality of your rest.”
Experts warn that open windows act as an open invitation for insects and pests, particularly as temperatures rise. From mosquitoes and moths to spiders and midges, night-time pests are drawn to light and warmth — and an unprotected bedroom window is the perfect entry point.
“We’ve seen an increase in calls about stings, bites and insect-related allergic reactions that started with a window left open overnight,” says one pest control specialist.
While some people swear by night air to help them drift off, open windows may actually worsen sleep quality, not improve it.
- Sudden temperature drops during the night can disrupt REM cycles
- Outdoor noise (cars, wind, foxes) can cause micro-awakenings
- Early sunrise light can throw off your body’s sleep-wake rhythm
The result? You might be waking up more tired than when you went to bed — and not know why.
Leaving a window open overnight can also impact your energy bills, especially during spring and autumn months. Cool night air can cause your central heating system to overwork as temperatures drop suddenly in the early morning hours, causing your thermostat to kick in — even when it’s not needed. Over time, that subtle heat loss could cost you hundreds in extra energy use.
Perhaps most importantly, home security experts warn that open windows — especially on ground floors or accessible levels — are one of the most common weak points burglars can exploit. According to police reports, a significant number of domestic break-ins happen between 2am and 5am, when households are asleep and defences are down. Even in safe neighbourhoods, an open or unlocked window is all it takes for an opportunist thief to gain access.
