HealthLearn why the first-night effect makes it harder to sleep in new places, how the brain stays more alert, who is most affected, and practical tips to sleep better while travelingSeveral factors can impact sleep in a new place beyond evolutionary vigilance. He is a victim of what sleep specialists call the first-night effect. "It’s assumed to be an adaptation response that the sleeping brain remains vigilant in this unfamiliar environment,” Wick said. While anyone can experience the first-night effect, Strauss said those who are more anxious at baseline are especially vulnerable. Mayeli said the first-night effect is not really anything to worry about, and people can easily make up for missing an hour or two of sleep for one night.