The advice from scientists in the US follows a field study that found people fell asleep about two hours earlier than usual when they were denied access to their gadgets and electrical lighting and went hiking with a tent.

A weekend in the wilds of the Rocky Mountains in Colorado helped reset people’s internal clocks and reversed the tendency of artificial light to push bedtime late into the night.

“Our modern environment has really changed the timing of our internal clocks, but also the timing of when we sleep relative to our clock,” said Kenneth Wright, director of the sleep and chronobiology lab at the University of Colorado in Boulder. “A weekend camping trip can reset the clock rapidly.”