http://www.fandeath.net/
Fan death is a South Korean urban legend which states that an electric fan, if left running overnight in a closed room, can result in the death (by suffocation, poisoning, or hypothermia) of those inside. This belief also extends to air conditioners. Fans manufactured and sold in Korea are equipped with a timer switch that turns them off after a set number of minutes, which users are frequently urged to set when going to sleep with a fan on.