# Catching a cold from air conditioning? **URL:** \ **Category:** Factual Questions\ **Created:** [February 20, 2008, 10:14pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442 "2008-02-20T22:14:28Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![blinkingblinking](https://avatars.discourse-cdn.com/v4/letter/b/ea5d25/32.png) [@blinkingblinking](https://boards.straightdope.com/u/blinkingblinking)\ **Post date:** [February 20, 2008, 10:14pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/1 "2008-02-20T22:14:28Z")
I thought this had been answered. But all the people at work say they catch colds from the air conditioning. I had thought it had been resolved that this was not true. One woman said her doctor told her that people can catch colds from air conditioning. “So it must be true.” ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [February 20, 2008, 10:56pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/2 "2008-02-20T22:56:19Z")
IANAD, but they may be referring to the fact that microbes tend to hang around unventilated rooms, such as those with air conditioning. So it’s not the A/C itself but the fact that someone with a cold has been in the room and the air hasn’t had chance to refresh that may be the real issue. Just a guess… ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [February 20, 2008, 11:32pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/3 "2008-02-20T23:32:48Z")
If your air conditioning traps moisture it may develop mold, and that can cause symptoms similar to rhinovirus. This may the the source of the story. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [February 21, 2008, 12:42pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/4 "2008-02-21T12:42:31Z")
Oh yeah…you can catch a cold from an A/C, esp. for lengthy periods of exposure to a chilly environment and/or having it blown directly on you for long periods. I was stuck in a cold, computer room working on a project for a week in the middle of summer. By the end of the week, I had a nice cold going. Now, I’m not going to debate how people catch colds, as it has never been settled, but I can only conclude the cold environment certainly weakened my immunity. When it happened, it was an obvious one-to-one relationship. I am a believer. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [February 21, 2008, 3:11pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/5 "2008-02-21T15:11:22Z")
People catch colds by being exposed to the rhino virus, for which they have no immunity. If you were never exposed to a certain strain, you will ‘get sick’ from that strain. If your immune system is rocking, you will have a shorter and easier duration most likely, but you will still have been infected. If cold air can create the virus out of nothing, please let us know. ---
**Author:** ![brossa](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/brossa/32/3040_2.png) [@brossa](https://boards.straightdope.com/u/brossa)\ **Post date:** [February 21, 2008, 3:17pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/6 "2008-02-21T15:17:55Z")
Maybe not a viral URI, but [bacterial pneumonia](http://en.wikipedia.org/wiki/Legionellosis#How_Legionnaires.27_disease_is_spread), yes. [QUOTE=Jinx] Oh yeah…you can catch a cold from an A/C, esp. for lengthy periods of exposure to a chilly environment and/or having it blown directly on you for long periods. I was stuck in a cold, computer room working on a project for a week in the middle of summer. By the end of the week, I had a nice cold going. Now, I’m not going to debate how people catch colds, as it has never been settled, but I can only conclude the cold environment certainly weakened my immunity. When it happened, it was an obvious one-to-one relationship. I am a believer. [/QUOTE] This is odd, because I’ve had a similar experience. Just last week, I got a cold, and I couldn’t for the life of me figure out why. Then I realized that I had been wearing a new pair of shoes that week. Damn shoes gave me a cold. Now I’ve switched back to my old shoes, so I will never get a cold again. ---
**Author:** ![picunurse](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@picunurse](https://boards.straightdope.com/u/picunurse)\ **Post date:** [February 21, 2008, 3:46pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/7 "2008-02-21T15:46:16Z")
If filters aren’t changed frequently enough, they can redistribute organisms. > [@jinx](#): > > Oh yeah…you can catch a cold from an A/C, esp. for lengthy periods of exposure to a chilly environment and/or having it blown directly on you for long periods. You are absolutely, 100% **WRONG**. I understand that you think you got a cold from the A/C, but you didn’t. If the filters were dirty, you may have gotten sick from organisms once trapped there, but it could have also been from the handle on a grocery cart, or maybe you mail carrier had a cold. ---
**Author:** ![blinkingblinking](https://avatars.discourse-cdn.com/v4/letter/b/ea5d25/32.png) [@blinkingblinking](https://boards.straightdope.com/u/blinkingblinking)\ **Post date:** [February 22, 2008, 7:43pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/8 "2008-02-22T19:43:13Z")
Anyone else? I thought the master had done a column on this but I cannot find it. ---
**Author:** ![Edward\_The\_Head](https://avatars.discourse-cdn.com/v4/letter/e/ce73a5/32.png) [@Edward\_The\_Head](https://boards.straightdope.com/u/Edward_The_Head)\ **Post date:** [February 22, 2008, 8:11pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/9 "2008-02-22T20:11:48Z")
[QUOTE=picunurse] You are absolutely, 100% **WRONG**. I understand that you think you got a cold from the A/C, but you didn’t. [/QUOTE] I’ve always wanted to know this then. Are you saying I can stand outside in 30 degree weather with no clothes on and not get sick? Because when I was in college I was sick for an entire semester because my roommate would open the window in the middle of the night and I would have freezing cold air down my back. I also tend to get the sniffles if I am waiting out in the cold for the train if I’m there for more then a few minutes. So you’re outright telling me that it’s impossible to get sick from being in the cold. ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [February 22, 2008, 8:29pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/10 "2008-02-22T20:29:16Z")
[QUOTE=Edward The Head] I’ve always wanted to know this then. Are you saying I can stand outside in 30 degree weather with no clothes on and not get sick? Because when I was in college I was sick for an entire semester because my roommate would open the window in the middle of the night and I would have freezing cold air down my back. I also tend to get the sniffles if I am waiting out in the cold for the train if I’m there for more then a few minutes. So you’re outright telling me that it’s impossible to get sick from being in the cold. [/QUOTE] [http://www.straightdope.com/classics/a4\_104.html](http://www.straightdope.com/classics/a4_104.html) According to this hack. > [@](#): > > The cold, wet feet, etc., don’t make you more susceptible to the common cold. Several researchers, obviously graduates of the Joseph Mengele School of Medicine, had people sit in cold tubs and whatnot for extended periods to see if they’d catch more colds. By and large they didn’t. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [February 22, 2008, 8:35pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/11 "2008-02-22T20:35:15Z")
[QUOTE=Edward The Head] I’ve always wanted to know this then. Are you saying I can stand outside in 30 degree weather with no clothes on and not get sick? Because when I was in college I was sick for an entire semester because my roommate would open the window in the middle of the night and I would have freezing cold air down my back. [/quote] What kind of sick? You had an ongoing cold? Depends on what you mean by “sick.” Obviously in extreme cases you get hypothermia, but the OP was asking about colds. Exposure to cold can also cause muscular soreness; the cold can cause muscle contractions which could over a period of time lead to aches or soreness. I think this is the origin of archaic phrases like “a cold in my shoulder.” > [@](#): > > I also tend to get the sniffles if I am waiting out in the cold for the train if I’m there for more then a few minutes. So you’re outright telling me that it’s impossible to get sick from being in the cold. Having the sniffles does not mean you have a cold, or are even sick at all. A runny nose is a reaction of the mucous membranes to cold, and goes away when you’re warm again. It’s just a reaction to the temperature, like getting goosebumps or shivering. ---
**Author:** ![Edward\_The\_Head](https://avatars.discourse-cdn.com/v4/letter/e/ce73a5/32.png) [@Edward\_The\_Head](https://boards.straightdope.com/u/Edward_The_Head)\ **Post date:** [February 22, 2008, 8:45pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/12 "2008-02-22T20:45:42Z")
[QUOTE=CookingWithGas] What kind of sick? You had an ongoing cold? Depends on what you mean by “sick.” Obviously in extreme cases you get hypothermia, but the OP was asking about colds. Exposure to cold can also cause muscular soreness; the cold can cause muscle contractions which could over a period of time lead to aches or soreness. I think this is the origin of archaic phrases like “a cold in my shoulder.” [/quote] No not a cold, and I never went to the doctor when I was sick since I was in college so I don’t know what I had exactly. I coughed constantly for a good two months or so. > [@](#): > > Having the sniffles does not mean you have a cold, or are even sick at all. A runny nose is a reaction of the mucous membranes to cold, and goes away when you’re warm again. It’s just a reaction to the temperature, like getting goosebumps or shivering. Again I understand that you can’t get a cold, from being out in the cold, I’m just talking sick. I’ve been told hundreds of times that you can not get sick from being out in the cold, yet I’ve gotten sick a couple of times from waiting for the train for an hour, no place to wait inside, or just two weeks ago from riding the motorcycle in sub 30 degree weather. Mostly it’s a cough that doesn’t go away for a week or so, and not a normal cough, but nice mucusy coughs. I’m asking about being cold and getting sick, and not getting a cold from being cold. ---
**Author:** ![herownself](https://avatars.discourse-cdn.com/v4/letter/h/8baadc/32.png) [@herownself](https://boards.straightdope.com/u/herownself)\ **Post date:** [February 22, 2008, 11:36pm UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/13 "2008-02-22T23:36:48Z")
Again, it is just not possible to become sick, i.e. ‘mucus-y’ cough for 2 weeks, from being in the cold or as a result of being cold. One’s nose often runs when out in the cold, that’s a reaction that the nose has to being out in the cold. Get warm, nose stops running. And the mucus that runs from the nose in this situation will be clear and loose - unless one is already sick. Being sick involves exposure to and then failure of immune response to (almost always) viruses or bacteria. I can’t remember what Legionnaire’s disease was, but I have a sneaking suspicion it was mold - that’s uncommon. The virus or bacteria then settles, or colonizes, in some part of the respiratory system: sinuses, throat, lungs. Antibiotics can help if you have a bacterial infection. NOT if you have a viral infection. After a while, the immune system kicks in to gear and kicks the stuff out. There are 2 ways these viruses or bacteria (but it’s usually viruses) are usually transmitted. First, they may be aerosolized and spread through the air when an infected person coughs or sneezes. Then the unsuspecting not-yet-sick person inhales then along with the air they breathe, and become infected and all nasty-sick themselves. This is why we cover our mouthes when we cough and sneeze into a tissue or hankie. It’s not just good manners, it’s good public health! This method of transmission is also why there are more colds in winter than summer, possibly explaining the association with cold. When it is cold outside, people tend to spend more time indoors together, increasing the likelihood that a virus, if present, will be spread. The second method of transmission is more sneaky. It involves unconscious acts that we do every day: touching things. The trick is that other people touch things too. If someone with a cold has just coughed politely into their hand, and then gone to make a copy on the copier, they will touch the copier. You might come by 5 minutes later and also touch the copier, because you need to make a copy as well. It may be that some of the viruses causing coughy-person’s cough will have transferred on to the copy button, and been sturdy enough to hang out for a while. Then they get on your hand, but you don’t know it. Then it’s lunch time, and you eat the sandwich you brought from home, ingesting the virus. Or you touch your eyes, or your mouth without even really noticing. Now you’ve given yourself the virus. You may or may not get sick. This happens all the time. This is why hand-washing frequently is important - for you as prevention and for the sick person to help avoid spreading the illness. Maybe you rode your motorcycle in to work on the day someone was coughing in the 3-hour meeting. But the fact that you got cold had noting to do with the fact that you were exposed to the virus. Coincidence. I’m not a doctor, but I was a biology major for a while, and this stuff is basic. I am an epidemiologist, if that helps, so I do know something about transmission of infectious diseases in populations. But really, without offense, this is basic biology. ---
**Author:** ![gonzomax](https://avatars.discourse-cdn.com/v4/letter/g/e8c25b/32.png) [@gonzomax](https://boards.straightdope.com/u/gonzomax)\ **Post date:** [February 23, 2008, 2:28am UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/14 "2008-02-23T02:28:55Z")
[http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35869](http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35869) Cold myths rebutted. ---
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [February 23, 2008, 2:36am UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/15 "2008-02-23T02:36:42Z")
[QUOTE=picunurse] You are absolutely, 100% **WRONG**. I understand that you think you got a cold from the A/C, but you didn’t. If the filters were dirty, you may have gotten sick from organisms once trapped there, but it could have also been from the handle on a grocery cart, or maybe you mail carrier had a cold. [/QUOTE] Obviously you can’t get colds from an A/C because colds are caused by viruses, but there have been [studies](http://www.medpagetoday.com/Pulmonary/URIstheFlu/tb/2136) in the past handful of years, though, that suggest that the old wives are right and prolonged exposure to cold & wet can reduce your resistence to cold. I’m not sure how much weight to give this vs. the opposite results from a nazi scientist. I know I got a terrible chest cold two weeks ago after a. being out in the pouring rain shoveling snow for an hour b. being exposed before and after to sick coworkers. I might have caught the cold anyway, but I can’t imagine the time I spent trying to dislodge my car from the snowbank helped any. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [February 23, 2008, 3:11am UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/16 "2008-02-23T03:11:35Z")
[QUOTE=picunurse] If filters aren’t changed frequently enough, they can redistribute organisms. You are absolutely, 100% **WRONG**. I understand that you think you got a cold from the A/C, but you didn’t. If the filters were dirty, you may have gotten sick from organisms once trapped there, but it could have also been from the handle on a grocery cart, or maybe you mail carrier had a cold. [/QUOTE] Wait a minute. Per your explanation, he’s not wrong at all, he’s 100% right. If filters can redistribute organisms like you said, then you can get a cold from A/C. Perhaps not from the temperature of the air, but certainly from the junk floating around in it. ---
**Author:** ![picunurse](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@picunurse](https://boards.straightdope.com/u/picunurse)\ **Post date:** [February 23, 2008, 3:19am UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/17 "2008-02-23T03:19:19Z")
[QUOTE=Edward The Head] I’ve always wanted to know this then. Are you saying I can stand outside in 30 degree weather with no clothes on and not get sick? Because when I was in college I was sick for an entire semester because my roommate would open the window in the middle of the night and I would have freezing cold air down my back. I also tend to get the sniffles if I am waiting out in the cold for the train if I’m there for more then a few minutes. So you’re outright telling me that it’s impossible to get sick from being in the cold. [/QUOTE] The question I was answering was specific to a cold. Cold, damp environments often have an over-growth of molds, which can cause illness, as well. One other thing is that when one is in a new environment, like college, there are all kinds of new organisms to be exposed to. When I was a travel nurse, I was usually sick the second week at each assignment. Some were in warm climates, some were in cold. I got sick from being exposed to organisms I had no immunity to. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [February 23, 2008, 7:29am UTC](https://boards.straightdope.com/t/catching-a-cold-from-air-conditioning/438442/18 "2008-02-23T07:29:43Z")
[QUOTE=herownself] … I can’t remember what Legionnaire’s disease was, but I have a sneaking suspicion it was mold … [/QUOTE] It wasn’t (it’s the first thing I thought of too), it was, > [@](#): > > [Legionella](http://en.wikipedia.org/wiki/Legionella) … a Gram negative bacterium, including species that cause legionellosis or Legionnaires’ disease, most notably L. pneumophila. Legionella are common in many environments, with at least 50 species and 70 serogroups identified. … > … Legionella acquired its name after a July, 1976 outbreak among people attending a convention of the American Legion in Philadelphia. The mystery disease sickened 221 persons, causing 34 deaths. In that bicentennial year, a pandemic among U.S. war veterans was widely publicized and produced a national panic. On January 18, 1977 the causative agent was identified as a previously unknown bacterium … > [@](#): > > … [Legionellosis](http://en.wikipedia.org/wiki/Legionellosis#How_Legionnaires.27_disease_is_spread) infection occurs after inhaling water droplets that originated from a water source contaminated with Legionella. It must be inhaled through a fine aerosol of tiny water droplets that are strung with the bacteria. This often comes from poorly ventilated areas such as prisons where a condensating air conditioner can spread it throughout the entire room, infecting anyone not immune to the strand of bacteria. Potential sources of such contaminated water include cooling towers used in industrial cooling water systems as well as in large central air conditioning systems, evaporative coolers, hot water systems, showers, whirlpool spas, architectural fountains, room-air humidifiers, ice making machines, misting equipment and similar disseminators that draw upon a public water supply. The disease may also be spread in a hot tub if the filtering system is defective. Freshwater ponds, creeks, and ornamental fountains are also potential sources of Legionella. > > Legionella will grow in water at temperatures from 20 °C to 50 °C (68 °F to 122 °F). However, the bacteria reproduce at the greatest rate in stagnant water at temperatures of 35 °C to 46 °C (95 °F to 115 °F). > > Legionella longbeachae, an organism in the Legionella family, is found in soils and compost. Thus, the dust from purchased bags of soil, compost, or potting mix is also a potential source of Legionella … so not the air conditioning but the air conditioner itself. CMC +fnord!