# Comment on: Will sleeping in a closed room with an electric fan cause death? **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [June 24, 2013, 11:03am UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771 "2013-06-24T11:03:00Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [June 24, 2013, 11:03am UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/1 "2013-06-24T11:03:00Z")
I’m surprised at the lack of research here. Several clues: 1. Happens only in Korea. 2. Happens only during the summer. 3. Happens only in a closed room. Therefore: 1. What is it about Korea that is different than the rest of the world? Answer: [Underfloor heating](http://en.wikipedia.org/wiki/Underfloor_heating). 2. Why does it happen only during the summer? Answer: the underfloor heating system is off because it is not needed, so people will close up a room thinking that it is safe to do so (see below.) 3. Why does it happen only in a closed room? Answer: because the underfloor heating system is off, the normal ventilation system for that system is also off causing a buildup of gases. In buildings that have an older form of coal-based underfloor heating, carbon monoxide death is a well-known hazard causing modern buildings to have a water-based instead of coal based heating system. Also note that in Korea, propane is the preferred source of heat for water, underfloor heating, and cooking. In general, anytime you are in Korea, it’s a bad idea to stay in a closed room. [This article](http://jech.bmj.com/content/39/1/79.full.pdf) shows a 201% spike in carbon monoxide deaths in Korea during winter, when the underfloor heating system is most utilized. When I was there, this was a known danger that we were warned about. However, in summer, when people think the underfloor system is off, that doesn’t mean it’s not being used. In some buildings (like the one I stayed in) the hot water for the shower went through the underfloor system. We had to turn it on when we wanted to take a shower, summer or winter. * * * LINK TO COLUMN: [Will sleeping in a closed room with an electric fan cause death? - The Straight Dope](http://www.straightdope.com/columns/read/1245/will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death) ---
**Author:** ![yellowjacketcoder](https://avatars.discourse-cdn.com/v4/letter/y/4bbf92/32.png) [@yellowjacketcoder](https://boards.straightdope.com/u/yellowjacketcoder)\ **Post date:** [June 24, 2013, 6:07pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/2 "2013-06-24T18:07:02Z")
So your thesis is that it has nothing to do with the fans, but with the underfloor heating? Congrats, you agree with Cecil. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [June 24, 2013, 6:46pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/3 "2013-06-24T18:46:17Z")
> [@yellowjacketcoder](#): > > So your thesis is that it has nothing to do with the fans, but with the underfloor heating? Congrats, you agree with Cecil. Cecil says nothing about underfloor heating. Inasmuch as he gives an explanation at all, he seems to imply that the deaths that Koreans attribute to fans are most likely just random deaths from unrelated causes. I don’t know if **Superhal** is right, but at least he has a theory, that does not sound too crazy, as to why people in Korea, in particular, might have an elevated tendency to die from sleeping in unventilated rooms. I would want to see more evidence than he gives, however, that underfloor heating is particularly common in Korea. The first link in the OP does suggest that it is traditional there, but also implies that its dangers are well recognized in modern Korea, and it is traditional in other places (including China, according to the link) where there is no tradition of belief in “fan death”. [Link to Cecil’s article.](http://www.straightdope.com/columns/read/1245/will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death) ---
**Author:** ![Crocodiles\_And\_Boulevards](https://avatars.discourse-cdn.com/v4/letter/c/ee7513/32.png) [@Crocodiles\_And\_Boulevards](https://boards.straightdope.com/u/Crocodiles_And_Boulevards)\ **Post date:** [June 24, 2013, 7:24pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/4 "2013-06-24T19:24:26Z")
> [@njtt](#): > > Cecil says nothing about underfloor heating. Inasmuch as he gives an explanation at all, he seems to imply that the deaths that Koreans attribute to fans are most likely just random deaths from unrelated causes. > > I don’t know if **Superhal** is right, but at least he has a theory, that does not sound too crazy, as to why people in Korea, in particular, might have an elevated tendency to die from sleeping in unventilated rooms. I would want to see more evidence than he gives, however, that underfloor heating is particularly common in Korea. The first link in the OP does suggest that it is traditional there, but also implies that its dangers are well recognized in modern Korea, and it is traditional in other places (including China, according to the link) where there is no tradition of belief in “fan death”. > > [Link to Cecil’s article.](http://www.straightdope.com/columns/read/1245/will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death) I can vouch, at least anecdotally, that underfloor heating is still quite prevalent in Korean households. Here’s an excerpt from an interesting paper on it: > **[Industry Documents Library](https://www.industrydocuments.ucsf.edu/tobacco/)** ---
**Author:** ![Crisis\_Worker](https://avatars.discourse-cdn.com/v4/letter/c/838e76/32.png) [@Crisis\_Worker](https://boards.straightdope.com/u/Crisis_Worker)\ **Post date:** [June 28, 2013, 8:29am UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/5 "2013-06-28T08:29:48Z")
I have a hard time sleeping without an electric fan blowing on my face. Unless I am the walking dead, I can assure you, sleeping with an electric fan in a closed room does not cause death. (Source- 36 years of sleeping with an electric fan running in a closed room). ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [June 28, 2013, 3:52pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/6 "2013-06-28T15:52:12Z")
Side question: what about the fan in the face helps you sleep? ---
**Author:** ![Lanzy](https://avatars.discourse-cdn.com/v4/letter/l/74df32/32.png) [@Lanzy](https://boards.straightdope.com/u/Lanzy)\ **Post date:** [June 28, 2013, 9:19pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/7 "2013-06-28T21:19:48Z")
I don’t know if they still use it but when I was in Korea I was warned about the rise in carbon monoxide due to floors heated with ondol (might have misspelled that but it is pretty close) which is pretty much a big piece of charcoal. Had nothing to do with fans. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [July 17, 2013, 6:21pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/9 "2013-07-17T18:21:51Z")
I asked a friend of mine who grew up in South Korea, and is back there now, teaching ESL. She said the fans-are-dangerous urban legend is pretty widepread there. ---
**Author:** ![eastcheap](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@eastcheap](https://boards.straightdope.com/u/eastcheap)\ **Post date:** [July 18, 2013, 3:52am UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/10 "2013-07-18T03:52:34Z")
What I want to know is: If you have a cat and a fan in the same room, would that double your risk? ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [July 18, 2013, 1:47pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/11 "2013-07-18T13:47:34Z")
> [@Superhal](#): > > because the underfloor heating system is off, the normal ventilation system for that system is also off causing a buildup of gases. In buildings that have an older form of coal-based underfloor heating, carbon monoxide death is a well-known hazard causing modern buildings to have a water-based instead of coal based heating system. I’m curious – what’s a coal-based underfloor heating system like? I would assume a coal-fired boiler and a water pump, but obviously that’s not what you mean because the coal-fired boiler wouldn’t be stupidly placed under the floor. I live in China, and my cold water heater is also the floor heater, and I know where the natural gas vents to. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [July 18, 2013, 3:15pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/12 "2013-07-18T15:15:22Z")
> [@eastcheap](#): > > What I want to know is: If you have a cat and a fan in the same room, would that double your risk? And what if the cat is buttered? Would that be a factor? > **[Buttered cat paradox](https://en.wikipedia.org/wiki/Buttered_cat_paradox)** > > The buttered cat paradox is a common joke based on the combination of two adages: > The paradox arises when one considers what would happen if one attached a piece of buttered toast (butter side up) to the back of a cat, then dropped the cat from a large height. The buttered cat paradox, submitted by artist John Frazee of Kingston, New York, won a 1993 Omni magazine competition about paradoxes. The basic premise, stating the conditions of the cat and bread and posed as a question, was presented in... ---
**Author:** ![Beware\_of\_Doug](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Beware\_of\_Doug](https://boards.straightdope.com/u/Beware_of_Doug)\ **Post date:** [July 18, 2013, 6:10pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/13 "2013-07-18T18:10:03Z")
> [@eastcheap](#): > > What I want to know is: If you have a cat and a fan in the same room, would that double your risk? I have slept in closed rooms with both fan and kitteh. She is dead. I am alive. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 18, 2013, 6:13pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/14 "2013-07-18T18:13:40Z")
What if you slept in Schrodinger’s box with a cat and a fan? ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 18, 2013, 6:16pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/15 "2013-07-18T18:16:33Z")
> [@TriPolar](#): > > What if you slept in Schrodinger’s box with a cat and a fan? What is it with fans and cats? I’ve yet to meet a fan that didn’t go on endlessly about her kitty-children. I stopped sleeping with them years ago. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 18, 2013, 6:45pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/16 "2013-07-18T18:45:36Z")
I tried to have sex with a fan once, but it cut me off. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 18, 2013, 6:57pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/17 "2013-07-18T18:57:32Z")
> [@Czarcasm](#): > > I tried to have sex with a fan once, but it cut me off. You should have hit on that Dyson beauty. Nothing but smooth, sensuous curves that can blow all day. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [September 15, 2013, 10:00pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/18 "2013-09-15T22:00:10Z")
A later discussion of the topic: [How wide discussed is "fan death" as a myth in South Korea? - Factual Questions - Straight Dope Message Board](http://boards.straightdope.com/sdmb/showthread.php?t=652671) ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [September 17, 2013, 2:36am UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/19 "2013-09-17T02:36:32Z")
> [@Elendil\_s\_Heir](#): > > A later discussion of the topic: [How wide discussed is "fan death" as a myth in South Korea? - Factual Questions - Straight Dope Message Board](http://boards.straightdope.com/sdmb/showthread.php?t=652671) By later I think you mean earlier. ---
**Author:** ![J2Cam85\_hotmail.co.kr](https://avatars.discourse-cdn.com/v4/letter/j/f04885/32.png) [@J2Cam85\_hotmail.co.kr](https://boards.straightdope.com/u/J2Cam85_hotmail.co.kr)\ **Post date:** [September 25, 2013, 5:05pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/20 "2013-09-25T17:05:08Z")
Your explanation in terms of carbon monoxide poisoning lends a sadly plausible air to the supersitious concept that a fan can cause death in a sealed room. However, it is merely a matter of semantics to show that it is not the fan that causes death at all, but in fact improperly combusted charcoal. Now, if you can explain to me why Koreans actually believe (as confirmed by a taxi driver who claimed to be a traditional medic in his spare time) that eating gimchi will prevent the contraction of HIV, then I will gladly eat your suspicious pubic bacteria (for details on which, please see the relevant thread). ---
**Author:** ![J2Cam85\_hotmail.co.kr](https://avatars.discourse-cdn.com/v4/letter/j/f04885/32.png) [@J2Cam85\_hotmail.co.kr](https://boards.straightdope.com/u/J2Cam85_hotmail.co.kr)\ **Post date:** [September 25, 2013, 5:06pm UTC](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771/21 "2013-09-25T17:06:15Z")
This isn’t a proper sentence. Please be less Irish. [Next page](https://boards.straightdope.com/t/comment-on-will-sleeping-in-a-closed-room-with-an-electric-fan-cause-death/661771.md?page=2)