Back in the day when serving in Korea the wife and I had to move out of one house heated by an ondol system, a series of heated pipes that run under the floors of a residence, due to carbon monoxide leaks. By regulations, U.S. service members living off the base were required to live in homes that had been upgraded to use heated water pipes in the floor instead of the more dangerous hot air systems that were notorious for leaking poison gas. One morning shortly after moving into our new apartment the wife and I woke up each of us with pounding headaches and nausea. After our IQ’s returned to normal we decided “We’re outta here.” We discovered the landlord had lied about what heating system he had installed, being greedy for rent money. We were lucky we woke up at all.
The ondol heating systems may be behind the Korean urban myth of “fan death” that remains a concern primarily through fear-mongering by the media. In the public panic over illness or death that may have been caused by carbon monoxide poisoning it was often blamed on fans “stealing the air” or dehydrating sleepers. Most fans, even those sold today, have a timer that shuts the device off not to save electricity but to prevent death. That a fan is in the room of a person allegedly affected by a “fan death” is incidental. The fan death myth is persistent and even the skeptical blame it on dehydration and suffocation using rather shaky science to support their beliefs. But more than likely fans are blamed because one happens to be present in the room of the elderly or ill. more likely explanation that death through natural causes or carbon monoxide is ignored in favor of the scary idea that death can strike anyone, anywhere caused by nothing more than a gentle breeze.
The remote possibility may be that if a fan was involved in a death or illness at all it could have been from disturbing carbon monoxide gas that had settled under the floors from leaking heating pipes. It is possible the gas may have been disturbed by moving air from a fan that caused it to swirl and rise up through the floor to the level of a sleeping person who, in traditional Korean homes slept on mats on the floor, could then have then been in direct contact with the gas. Any “fan death” reports that had a basis in fact would probably have come from the passing of elderly residents in older style homes heated by older ondol. It is unlikely the one or two deaths per year attributed to “fan death” occur in modern homes with safer heating systems and are probably due to natural causes.