Editing Common cold (section)

==Epidemiology==
The common cold is the most common human disease<ref name=E1/> and affects people all over the globe.<ref name=Text2007/> Adults typically have two to three infections annually,<ref name=CE11/> and children may have six to ten colds a year (and up to twelve colds a year for school children).<ref name="AFP07"/> Rates of symptomatic infections increase in the elderly due to declining immunity.<ref name="E78">Eccles p. 78</ref>

===Weather===
A common misconception is that one can "catch a cold" merely through prolonged exposure to cold weather.<ref>{{cite news |vauthors=Zuger A |title='You'll Catch Your Death!' An Old Wives' Tale? Well.. |newspaper=[[The New York Times]] |date=4 March 2003 |url=https://www.nytimes.com/2003/03/04/science/you-ll-catch-your-death-an-old-wives-tale-well.html |url-status=live |archive-url=https://web.archive.org/web/20170322034343/http://www.nytimes.com/2003/03/04/science/you-ll-catch-your-death-an-old-wives-tale-well.html |archive-date=22 March 2017}}</ref> Although it is now known that colds are viral infections, the prevalence of many such viruses are indeed seasonal, occurring more frequently during cold weather.<ref>Eccles p. 79</ref> The reason for the seasonality has not been conclusively determined.<ref name=nhs>{{cite web |title=Common cold – Background information |url=http://www.cks.nhs.uk/common_cold/background_information/prevalence |publisher=National Institute for Health and Clinical Excellence |access-date=19 March 2013 |url-status=dead |archive-url=http://webarchive.nationalarchives.gov.uk/20121115105310/http%3A//www.cks.nhs.uk/common_cold/background_information/prevalence |archive-date=15 November 2012}}</ref> Possible explanations may include cold temperature-induced changes in the respiratory system,<ref name="EcclesPg" /> decreased immune response,<ref name="Mourtzoukou"/> and low humidity causing an increase in viral transmission rates, perhaps due to dry air allowing small viral droplets to disperse farther and stay in the air longer.<ref>Eccles p. 157</ref>

The apparent seasonality may also be due to social factors, such as people spending more time indoors near infected people,<ref name="EcclesPg">Eccles p. 80</ref> and especially children at school.<ref name=Text2007/><ref name=nhs/> Although normal exposure to cold does not increase one's risk of infection, severe exposure leading to significant reduction of body temperature ([[hypothermia]]) may put one at a greater risk for the common cold: although controversial, the majority of evidence suggests that it may increase susceptibility to infection.<ref name="Mourtzoukou">{{cite journal |vauthors=Mourtzoukou EG, Falagas ME |title=Exposure to cold and respiratory tract infections |journal=The International Journal of Tuberculosis and Lung Disease |volume=11 |issue=9 |pages=938–43 |date=September 2007 |pmid=17705968}}</ref>