Why You Sleep Differently Away From Home — And What the Research Says Can Help

If you’ve ever had a restless first night in a hotel, you’re not imagining it. Scientists have a name for it — the “first night effect” — and recent research has uncovered what’s actually happening in your brain when you try to sleep somewhere new.

A 2016 study from Brown University, published in Current Biology, used advanced neuroimaging to monitor brain activity during sleep in an unfamiliar environment. The researchers found that on the first night, one brain hemisphere — specifically the left — remained in a lighter state of sleep than the right during deep slow-wave sleep. This hemisphere showed heightened responsiveness to unexpected sounds, faster awakening, and quicker reaction times (Tamaki et al., 2016).

The researchers concluded that this is likely a survival mechanism — similar to how dolphins and certain birds sleep with one hemisphere at a time to stay alert to predators. In humans, this asymmetry disappeared by the second night, confirming that it’s specifically a response to an unfamiliar environment.

A follow-up study by the same team, published in Frontiers in Neuroscience, found that a similar vigilance response also occurs during REM sleep on the first night, with the brain deploying resources normally used for internal mental activity — like dreaming — toward monitoring the external environment instead (Tamaki et al., 2019).

Beyond what’s happening in the brain, the physical sleep environment matters significantly. A study published in Tourism Management analysed hotel guest reviews and found that sleep quality was influenced by a combination of personal factors (age, gender, traveller type) and hotel characteristics — particularly noise levels, room temperature, mattress quality, and light control (Mao et al., 2018).

Research led by Harvard sleep scientist Rebecca Robbins confirmed these findings, identifying bed linen quality, pillow comfort, and guestroom noise as the hotel attributes most closely linked to both sleep quality and overall guest satisfaction (Robbins et al., 2022).

Interestingly, a study in the International Journal of Hospitality Management found that not everyone sleeps worse away from home. Some guests actually reported better sleep in hotels than at home — a phenomenon the researchers attributed to the fact that hotel rooms are associated purely with rest, unlike home bedrooms that often double as workspaces or screen-time zones (Xiong et al., 2020).

The first night effect is involuntary — you can’t simply decide to turn it off. But the research points to several strategies that can reduce its impact and support better sleep in unfamiliar settings.

Reduce unfamiliar stimuli. Since the brain’s vigilance response is triggered by an unfamiliar environment, anything that reduces novelty may help. Research on the first night effect suggests that familiar cues — a consistent pre-sleep routine, familiar scents, or even bringing your own pillowcase — could help signal safety to the brain.

Control light and noise. The Tourism Management study identified these as the most common environmental disruptors of hotel sleep. Using blackout curtains, earplugs, or white noise can help reduce the sensory input that keeps the brain’s surveillance system active.

Keep the room cool. As covered in earlier research on sleep and temperature, a room between 18–22°C supports the body’s natural thermoregulation during sleep. This is particularly relevant in hotels where guests may not think to adjust the thermostat before bed.

Maintain your wind-down routine. A meta-analysis in Sleep Medicine Reviews found that behavioural sleep interventions — including consistent sleep timing, relaxation techniques, and reduced stimulation before bed — had a medium-sized positive effect on sleep quality (Friedrich & Schlarb, 2018). These strategies are portable: they work just as well in a hotel room as they do at home.

Limit screen use before bed. The temptation to scroll through your phone in an unfamiliar room is strong, but as research consistently shows, blue light from screens suppresses melatonin and delays sleep onset — exactly what you don’t need when your brain is already on high alert.

Sleeping poorly on your first night away from home isn’t a personal failing — it’s your brain doing exactly what evolution designed it to do. Understanding that can help take the frustration out of the experience. And while you can’t override the first night effect entirely, managing your environment and maintaining a consistent routine can meaningfully improve how well you sleep when you’re away from your own bed.