I hadn’t heard about this before. But I guess it’s a well-known truism. PRI even did a report on the belief in Korea that leaving a fan on overnight could cause death and many fans in Korea have timers to make sure no one forgets before going to sleep.

As PRI says, “A number of websites espouse theories about the origins of fan death. One way Koreans believe your fan can kill you is hypothermia. As the theory goes, if there’s a fan blowing all night, it may cause your body temperature to cool down enough to cause death.

They also worry about suffocation: that a fan left on in a sealed room just circulates the heat and prevents proper breathing. There’s even a theory that the South Korean government concocted the idea fan death to persuade citizens to decrease electrical use during an energy crisis in the ’70s. Of course, there’s no evidence to support any of these theories.”

Of course, even more popular is the idea that putting ice in...