If you can’t sleep in a new place, you are experiencing something sleep scientists call the first-night effect. On your first night somewhere unfamiliar, like a hotel, a relative’s spare room or a new home, part of your brain stays more alert than usual, keeping watch while the rest of you sleeps. The result is lighter, more broken sleep with more waking. It is a normal, protective reflex rather than a sign that something is wrong, and for most people it eases noticeably by the second night.
With holiday travel season approaching, it is a useful thing to understand, because knowing why it happens takes a lot of the frustration out of it.
What is the first-night effect?
The first-night effect was described more than half a century ago. In 1966, Agnew, Webb and Williams published a study in Psychophysiology in which 43 people slept for four consecutive nights in a sleep laboratory while their brain activity was recorded. On the first night, people spent more time awake, had less REM sleep and took longer to reach the deepest and REM stages of sleep. By the second night, those differences had largely faded.
The finding mattered so much that sleep labs still account for it today. Researchers often treat the first night as an adaptation night and focus on the nights that follow, because the first one does not reflect how a person normally sleeps. If you have ever had a sleep study and worried that your night in the lab was unusually poor, this is part of the reason.
Why can’t I sleep in a new place? Your brain is keeping watch
For decades, the first-night effect was mostly described rather than explained. A 2016 study in Current Biology by Tamaki, Bang, Watanabe and Sasaki offered a compelling explanation.
The researchers measured brain activity in volunteers during their first and second nights in a sleep lab. On the first night, during deep, slow-wave sleep, one hemisphere of the brain (usually the left) stayed noticeably more awake than the other. That more alert side also responded more strongly to unusual sounds played during sleep. On the second night, this imbalance was much weaker.
In other words, when you sleep somewhere new, your brain posts a night watch. The authors compared it to animals such as some birds and marine mammals, which can rest one half of the brain while the other stays alert. It is an old, sensible strategy: in an unfamiliar environment, it pays to be a little easier to wake.
So if you lie in a hotel bed hearing every lift, door and footstep, you are not imagining it. Your brain really is listening more closely than it does at home. If you are a light sleeper even in familiar surroundings, the effect may feel stronger still.
How long does the first-night effect last?
For most people, the worst of it is the first night. Both the original 1966 research and the 2016 brain-imaging study found that sleep settled considerably by night two. Frequent travellers sometimes notice it less over time, perhaps because new rooms start to feel less novel.
If you are also crossing time zones, the first-night effect stacks on top of jet lag, which can take several days to resolve. Our guide on how to beat jet lag covers that side of travel.
For new parents: travelling with a baby or toddler
When you travel with a little one, you are juggling two sets of first-night effects: yours and theirs. Unfamiliar sounds, light, smells and a different sleep space can unsettle babies and toddlers too, and the change in routine can make bedtime harder.
The most useful thing you can pack is your routine. In a study of 405 mothers and their infants and toddlers, Mindell and colleagues (2009, Sleep) found that introducing a consistent nightly bedtime routine helped children fall asleep faster and wake less often during the night, and that mothers’ mood improved too. On the road, the same bath, the same song or book and the same order of steps tell your child that, even in a new room, this is still bedtime.
A few other ideas that tend to help:
- Bring familiar sleep cues, such as the sleeping bag, white noise or comforter (for children old enough to have one) they use at home.
- Keep safe sleep basics the same as at home: your baby on their back, in their own firm, flat sleep space such as a travel cot, without pillows or loose bedding.
- Protect your own sleep where you can. If you are sharing a room with your baby, earplugs are usually not practical, but a sleep mask or a gentle fan can help you rest between wakes.
If travel has left you running on very little, sleep debt for parents looks at realistic ways to recover once you are home.
For perimenopause: when the new room is also too warm
If you are in perimenopause, sleeping away from home can bring an extra challenge: temperature. Guest rooms and hotel rooms are often warmer than your bedroom at home, and you may not have your usual cooling setup, breathable bedding or fan. A warm room gives your body less margin before a hot flash or night sweat wakes you, and that lands right on top of the brain’s first-night alertness.
A little preparation helps:
- Cool the room early. Turn the thermostat down or open a window before bed, and ask for a fan if there is one. Our post on whether it is bad to sleep with a fan on explains why moving air helps.
- Pack your own lightweight sleepwear and, if space allows, a breathable pillowcase.
- Keep water by the bed and a layer you can easily throw off.
If night sweats are a regular part of your nights, night sweats and sleep goes into more detail.
How can I sleep better in a new place?
You cannot fully switch off your brain’s night watch, but you can give it less to watch for.
- Make it familiar. Bring your own pillow or pillowcase, a familiar scent or your usual book. Familiar cues signal safety.
- Keep your routine. Go to bed and wake at roughly your usual times, and follow your normal wind-down steps. A bedtime routine for adults is a portable anchor.
- Soften unfamiliar sounds. Earplugs or a steady background sound such as a fan or white noise app can mask the doors, voices and footsteps that a watchful brain notices. See do earplugs help you sleep for more.
- Block unfamiliar light. Hotel curtains, standby lights and corridor light under the door are easy to fix with a sleep mask.
- Ask for a quieter room, away from lifts, ice machines and the street, if that is an option.
- Keep expectations low for night one. Lying awake thinking “I must sleep tonight” tends to keep sleep away. Telling yourself that a lighter first night is normal often makes it easier.
The calm version
Sleeping badly in a new place is not a sign that your sleep is broken. It is a small piece of very old protective wiring, and it usually eases by the second night. Bring familiar cues, keep your routine and go gently on yourself for night one. Mendtide’s morning briefing reads your Apple Health sleep data, so after a trip you can see your nights settling back into their usual rhythm rather than wondering whether they will.
A new room is a new place for your brain to keep watch over. Give it a night, and it will let you rest.