Electronic Portable Fans sold in Korea are equipped with a timer switch that shuts off the fan after a set number of minutes, which users are frequently urged to do when sleeping with a fan in their room. This “safety” modification is not unlike the convenient feature I enjoy with the fans operated within my home during the hot Virginian evenings and its cool mornings. It’s nice to not have to turn off the fan in the morning. However there is a common fear of a running fan which I believe is perpetuated by irresponsible media reporting.
Korean urban legend states too many options by which one could fall victim to killer electric fans. Some of these include the belief that:
– The fan creates a vacuum in a sealed room thereby causing suffocation due to lack of oxygen.
– The fan slices up all the oxygen and therefore causes suffocation.
– The fan uses up the supply of oxygen causing suffocation.
– The fan pointed at the face will prevent oxygen from being inhaled.
– The fan contributes to hypothermia, extreme low body temperature, essentially freezing the victim.
– The fan prevents the skin from breathing and therefore suffocating the victim
– The fan contributes to oxygen displacement in general.
Of course to most of us, these are simply absurd. So let’s ignore the fantastic (pun intended), and discuss a rational health safety concern. There is a point where a fan is ineffective due to being operated within a sealed room without proper ventilation. To most people this is common sense of course. It’s the concept of forced convection cooling; using a fan to move the air from a colder outside air concentration to a hotter indoor concentration or exhausted from the hotter indoor concentration. It is Newton’s Law of Cooling which describes the rate of heat loss of a body and contributes the rate of cooling to be proportionate to the surrounding environment. Using Newton’s Law we can reason that it is not probable that a portable electric fan could not effect a change in the ambient temperature great enough or quick enough to cause hypothermia. The converse of this would be hyperthermia.
Definition: Hyperthermia is an elevated body temperature due to failed thermoregulation. Hyperthermia occurs when the body produces or absorbs more heat than it can dissipate. When the elevated body temperatures are sufficiently high, hyperthermia is a medical emergency and requires immediate treatment to prevent disability or death.
Hyperthermia is the only plausible area to be concerned, but I fail to have found it documented amongst Korean cautions about portable electronic fan use or their contribution to fatalities (by fan). It follows however that if a sealed room, already at a greater temperature than the body can withstand, is running an electronic fan it would not be effective in cooling the body or the sealed room. Portable electronic fans simple move air, pushing the air, no matter the temperature. Therefore, a fan would simple move the hot air over a body attempting to cool itself. Without replenishing water, the human body will suffer of course.
EPA Excessive Heat Events Guidebook, Appendix B: Use of Portable Electric Fans during Excessive Heat Events, “Don’t use a portable electric fan in a closed room without windows or doors open to the outside.”
EPA Excessive Heat Events Guidebook, Appendix C: Excessive Heat EventsGuidebook in Brief, “Don’t direct the flow of portable electric fans toward [you] when room temperature is hotter than 90°f.”
It is important [for believers of Korean urban legend] to understand the explanation of why this is not recommended. To reiterate, when the body temperature reaches about 40°C, (104°F) or if the affected person is unconscious or showing signs of confusion, hyperthermia can occur. Hyperthermia is considered a medical emergency that requires treatment in a proper medical facility. In a hospital, more aggressive cooling measures are available, including intravenous hydration, gastric lavage with iced saline, and even hemodialysis to cool the blood.
EPA Excessive Heat Events Guidebook, Page 37, 4.2.2 Provide information on proper use of portable electric fans during EHEs, “The TWG also strongly recommends that, as part of a public education program, cities emphasize that portable electric fans are not the simple cooling solution they appear to be. Because of the limits of conduction and convection, using a portable electric fan alone when heat index temperatures exceed 99°f actually increases the heat stress the body must respond to by blowing air that is warmer than the ideal body temperature over the skin surface (American Medical Association Council on Scientific Affairs, 1997; CDC, 2004c). In these conditions, portable electric fans provide a cooling effect by evaporating sweat. The increased circulation of hot air and increased sweat evaporation can, however, speed the onset of heat-attributable conditions (e.g., heat exhaustion).”
The Guidebook goes on to explain prevention; “Thus, portable electric fans need to be used with caution and under specific circumstances during an EHE, such as exhausting hot air from a room or drawing in cooler air through an open window. Generally, portable electric fans may not be a practical and safe cooling mechanism during an EHE in homes that are already hot and are not air-conditioned; their use should be discouraged unless the fans are bringing in significantly cooler air from outside the dwelling. If a resident must stay in these dwellings, and if they are unable to access an air-conditioned environment, safer cooling approaches would include taking frequent cool showers and drinking cool, nonalcoholic fluids (e.g., ice water). Because of the importance of this issue, and the contradictory messages people may have received about using portable electric fans during EHEs, Appendix B provides a series of guidelines for fan use during EHEs.”
Fan death is comical to most non-Koreans because it just doesn’t make much sense and most of the urban legend beliefs are incredible and isolated within Korean urban legend. Furthermore, common sense states that it is the elderly (above 65 years) as well as infants and children or people already suffering from chronic medical conditions who are more prone to heat stress. Notwithstanding, it is good advice for everyone to drink plenty of water and other fluids as well as turning on a fan or dehumidifying air conditioning unit on the affected person for it may improve the effectiveness of the body’s evaporative cooling mechanisms (sweating).
Finally, it is an individual’s responsibility to get informed; get the facts. It is the duty of public officials to provide reliable and well-founded safety information. Citizens should review the various educational messages about EHEs for consistency with other messages and information on other issues.
List of Acronyms and Abbreviations
CDC – Centers for Disease Control and Prevention
CSA – Canadian Standards Approved
DHS U.S. – Department of Homeland Security
EHE – excessive heat event
EMS – emergency medical service
EPA U.S. – Environmental Protection Agency
NOAA – National Oceanic and Atmospheric Administration
NWS – National Weather Service
PCA – Philadelphia Corporation for Aging
SMSA – standard metropolitan statistical area
SSC – spatial synoptic classification
TWG – Technical Working Group
UL – Underwriter Laboratories
“Fan Death.” Wikipedia, the Free Encyclopedia. Web. 03 Aug. 2011. <http://en.wikipedia.org/wiki/Fan_death>.
“Newton’s Law of Cooling.” Undergrad Mathematics. Web. 03 Aug. 2011. <http://www.ugrad.math.ubc.ca/coursedoc/math100/notes/diffeqs/cool.html>.
“Excessive Heat Events Guidebook.” Excessive Heat Events Guidebook. Environmental Protection Agency (EPA), 24 May 2006. Web. 03 Aug. 2011. <http://www.epa.gov/hiri/about/pdf/EHEguide_final.pdf>.
Philadelphia Office of Mental Health & Mental Retardation. 2002. Fan Facts. Philadelphia, PA.
Toronto Public Health. 2002. Summer Safety: Fan Facts. Toronto, Ontario, Canada.
“CDC Extreme Heat.” CDC Emergency Preparedness & Response Site. Web. 03 Aug. 2011. <http://emergency.cdc.gov/disasters/extremeheat/index.asp>.
“CDC Extreme Heat | A Prevention Guide to Promote Your Personal Health and Safety.” CDC Emergency Preparedness & Response Site. Web. 03 Aug. 2011. <http://emergency.cdc.gov/disasters/extremeheat/heat_guide.asp>.
“Hyperthermia.” Wikipedia, the Free Encyclopedia. Web. 03 Aug. 2011. <http://en.wikipedia.org/wiki/Hyperthermia>.