Your bedroom is affecting your sleep… here’s why
Before investing in another sleep supplement, Oura ring, or tracking your REM, look at the room you sleep in.
We've become very good at turning sleep into a chore. There's magnesium before bed, blue-light-blocking glasses, sunrise alarms, sleep scores, and elaborate sleepmaxxing nighttime routines designed to get us into the deepest possible slumber. But while we're busy optimising our bodies, we might be overlooking something rather obvious: the room we're letting them sleep in.
A study published in ‘Building and Environment’ investigated how temperature and lighting work together to influence sleep quality during winter. Rather than looking at each factor in isolation like most studies, researchers used a controlled experiment to examine combinations of pre-sleep temperature, light intensity, and colour temperature. Their findings suggested that the interaction between these environmental conditions could matter more than any one factor alone, with temperature and light intensity particularly relevant to how quickly participants fell asleep. So in essence, it’s all about getting that balance right.
When the temperature drops outside, you aren’t alone in reaching to flick on your heating. It’s an obvious solution, right? But the warmest room isn't necessarily the most sleep-friendly one. Our bodies naturally undergo changes in temperature as we prepare for sleep. The environment around us can influence that process, which is one reason an overly warm bedroom or heavy bedding can make it harder to settle comfortably… even in those chilly winter months.
The NHS recommends keeping bedrooms comfortable and quiet, while the Sleep Foundation commonly cites around 16–18°C as a useful starting point for many adults. That isn't a universal prescription, though, and hey, if you prefer a hot room for your cold toes, then that can work too. Bedding, personal preference, health, and the temperature of your home all play a part.
Temperature isn't the only thing worth considering, though. Light helps regulate our circadian rhythm, the internal timing system that influences when we feel awake and sleepy. Bright light in the evening can interfere with the body's preparation for sleep, particularly when it comes from overhead lighting or screens close to bedtime. Colour temperature matters, too: lighting with a stronger blue component can have different effects on our biological clock from warmer lighting, although the impact depends on brightness, duration, and timing.
That doesn't mean you need to replace every bulb in your home with an expensive sleep-friendly alternative. Maybe just throw out those 2020 LED light strings, and start by switching to softer lighting during the hour before bed, drawing curtains against outdoor light, and keeping your phone from becoming the brightest object in the room.
In the morning, the opposite principle applies. Getting natural daylight can help reinforce the body's day-night rhythm, even when the weather is distinctly uninspiring. In winter, this can be trickier, but switching on your warm lighting can help your body feel like the sun is rising… until it eventually does.
So don’t go investing in a whole bedroom makeover to help you sleep better. The point isn't to create a perfectly engineered sleep chamber or another expensive wellness ritual, but to notice the conditions you sleep in and make small adjustments where possible.
Try keeping your room comfortably cool, reducing unnecessary light in the evening, and getting some daylight early in the day. If you wake up hot, consider lighter bedding or breathable sleepwear before buying another supplement.
It's also worth remembering that the 2026 experiment examined particular combinations of environmental conditions. Persistent sleep problems deserve proper attention, particularly if they affect your ability to function during the day. But for those of us chasing marginal gains through increasingly complicated routines, the simplest intervention might be to look around the room. Make those small steps, and you might feel more energised this winter. And we all need a bit of energy in these colder months where we can get it.
