Anyone who has spent a summer in Japan will likely be well- acquainted with natsubate, or "summer fatigue" — a general state of lethargy and tiredness, lack of concentration, sleeplessness and even mild depression.

Dealing with the relentless heat and humidity, which only lets up slightly in the evenings, is enough to get anyone down. Air conditioning helps, but as it often blasts out unpleasantly over-chilly air in many public spaces, it sometimes ends up making you feel worse.

Japanese people have come up with all kinds of ways of bringing relief to the dog days of summer, some of which go back to the times before air conditioning and electric fans. There are the obvious ones, such as drinking iced mugicha (roasted barley tea) and cold beer or snacking on kakigori (shaved ice with syrup) and slurping up cold soba or somen noodles. But if not done carefully, subsisting on cold food and drink can actually end up leaving you malnourished and even more fatigued.