It was interesting to see the following comment in Tomoko Otake's July 17 article, "How to survive summer fatigue," about natsubate (summer fatigue): "Turning air conditioning on throughout the night is often a cause of natsubate."

I've often heard this in Japan, but never anywhere else. What's wrong with keeping air conditioning switched on all night?

Even with air conditioning on at night, the temperature is still much higher than it is in winter, so it can't be a question of just temperature. The same applies to humidity (in winter there is very low humidity in Japan).

The article also states that it is very important to get a good night's sleep. If air conditioning helps that happen, I don't see the problem. Some people might possibly get a sore throat from air conditioning, but if you keep the filters clean, that shouldn't be a problem.

People work in offices with air conditioning turned on all day, so why should their needs at night be any different? I suspect that this may be just an "old wives' tale" invented to get people to save electricity.

tony fordyce