Hmm interesting question! The sun definitely makes me more sleepy and I think on a similar strand if I have been out in the sun a lot say when on holiday in a hot place I am more physically exhausted so I think that helps. The sun is definitely an energy drainer for me! It's worth noting though, that unless somewhere has air con, it might be more difficult to sleep because of the heat so it can be give and take! I have never been close to the poles but I can imagine that must be very disorienting, either way. Would be good to be able to just get up and go for a walk or something if you were having insomnia in the middle of the night but it's still light outside, though! Best Wishes, Lauren (Team Member)