Even worse is the extreme latitudes in summer! I tried sleeping under just a mosquito net in Alaska when the sun stayed up until 2am and rose again by 4. I brought a sleeping mask but found it hard to keep on, as we'd encountered three separate grizzlies earlier that day…

At lower latitudes, a full moon over snow is stunning and surreal when you can get away from local light sources - no flashlight required. Light at night (of appropriate color temp) is quite natural.