Korean Belief in Danger of Fans in Unventilated Rooms Ridiculed
By wchung | 11 May, 2025

The widely held Korean belief that sleeping in a hot unventilated room with the fan on can cause death has become something of an internet joke despite credible authority suggesting the belief is founded on well-understood scientific principles.

The so-called fan-death “myth” was recently ridiculed in a Salon piece authored by Ken Jennings. Referring to his own childhood years in Korea, he says:

Jennings then cites Korean American T. K. Park and his Ask a Korean blog as an example of “the rise of fan death trutherism” movement to counter the ridicule being heaped on Korean society for its persistent fear of fan death.

In a long, well-reasoned essay titled “Fan Death Is Real” Park confesses that he too was a fan-death skeptic until finding that the US Environmental Protection Agency and Centers for Disease Control have also recently warned against electric fan use in enclosed rooms.

Their rationale — with which Park agrees — is based on the principle that when the air temperature in the room rises above the normal healthy surface temperature of the skin, the fan doesn’t provide a cooling effect but instead creates a convection-oven effect that rapidly dehydrate a person by constantly drying the small amounts of cooling moisture produced by the sweat glands until the body is dehydrated.

Once the body runs out of water and electrolytes, the skin stops sweating, leaving the body’s surface temperature to rise to a point at which it is no longer dissipating the heat constantly generated by metabolic activity. Unrelieved, the situation could result in a potentially fatal rise in the core temperature. The core temperature normally varies only about 1 degree farenheit in either direction. If it reaches 104 degrees, potentially debilitating and fatal hyperthermia sets in unless the victim is promptly cooled through hydration and ventilation.

Thus, a person already dehydrated from exertions during a long hot humid Korean summer day who falls asleep with the windows closed and a fan blowing directly on his bare body may never awaken. While it’s impossible to fix the cause of many sleeping deaths, several in Korea have been attributed to the fan, giving rise to the widespread fear of sleeping with the fan on without cracking the window.

Skeptics of fan death have ridiculed the more common and easily understood explanations provided by some Korean authorities for the potential lethality of fans. One is hypothermia — leaving a fan blowing on your body may lower your core temperature to a fatal level. The other is asphyxiation — the force of a strong fan blowing on the face, especially of an infant, could make it difficult to breathe naturally and may asphyxiate him. While both situations would be unhealthy — and conceivably fatal to an infant or a person in poor health — they are unlikely to be fatal to most people.

Jennings chooses to join the scoffers after speaking with Dr. Laurence Kalkstein, a climatologist who had helped write the EPA’s heat guidelines. Kalkstein told Jennings that he felt that fan use could be a “minor” factor in causing heat stress and dehydration though during a 2008 visit to Korea the same scientist had bolstered the Korean view by talking about the potential dangers of fan use in a hot room.

“If an elderly person sticks a little table fan right in front of their face to try to cool off, and it’s just blowing 105-degree air around, it creates what’s called an evaporation opportunity,” Kalkstein explained to Jennings. “Moisture from the body evaporates a lot faster, and therefore unless you replenish it quickly enough, it can create a heat problem for you.”

“Hierarchy and deference to authority are important in Korean culture, which can make myth-busting a challenge,” write Jennings.

He then cites the fact that younger Koreans who participated in a recent email survey of his contacts are as skeptical of fan death as their western counterparts before concluding,“A decade of Internet skepticism seems to have accomplished what the preceding 75 years could not: convinced a nation that Korean fan death is probably hot air.”

Disregarding the questionable objectivity of young Koreans who are not only the author’s associates but probably grew up in air-conditioned apartments, the article commits the folly it seeks to poke fun at by confusing popular sentiment for established fact.

The experiences of several generations of Korean health officials whose only agenda was to warn of potential health hazards rather than cutting witty figures in online discussions — not to mention the less alarmist but serious warnings of US health officials — provide a more reliable assessment of the potential risk of sleeping in a hot room with the fan on and the windows shut. The fact that not everyone who has done so has died is no more a refutation of the dangers than the fact that not everyone who has been in an car wreck has died is a refutation of the potentially fatal consequences of reckless driving.