Use of air conditioning in hospitals, food storage and industries for different applications do have direct and indirect effects on environmental degradation as well as on human health however, cannot over weigh its advantages.   But the growing use of air conditioning for human comfort which was limited to a small section of society few decades back is not only due to the erratic and drastic climatic changes taking place with all-time summer heat records keeping buckling all over the world under the weight of rising global temperatures but also due to the growing nature of laziness in the coming generations and looking for all type of comfortability in their life.

Every one of us desire for a comfortable life style. However, comfortability and un-comfortability are a seesaw with its sides of affordability and non-affordability. Affordability and non-affordability, though no longer have remained confined to the social levels like high/middle/lower classes of society. If we can afford, we always go for all means of comfortability and use of air-conditioning is one of such means of life whose use or overuse is growing rapidly with people who can afford it.  Without going into the overall environmental consequences of the use or over use of air-conditioning, in this article, stress is laid on the health effects of being habitual to the use or over use of air conditioning.

Air-conditioning is perfectly fine for a smartly designed atmosphere which takes care of temperature, humidity and fresh air content with an optimum use but for the sake of comfort we would always like to stay as much maximum in air conditioned space. Bodies comfort sensors are sensitive to temperature (dry bulb) mainly, humidity to a lesser degree and totally disregard air quality. Most of the AC system, hence will give importance to human comfort neglecting health aspects.  People of today living and spending their most of the time in fully air-conditioned buildings are definitely with less stamina & fitness as compared to our old generation who spent their life without air conditioning with their body undergoing annual temperature variation, through their life time, showing surprising fitness throughout their lives. As it is not possible to stay in conditioned space 24/7hrs, one has to undergo sudden change in the exposed environment. Internal body programming gets confused. People are reported to be suffering from cardiac arrests due to such sudden changes of temperatures; however, it is yet to be medically concluded on its effect on the body when it is periodically undergoing sudden changes in climatic conditions.

Health effects of air conditioning

Everything in this world which is being invented by human has its own benefits and bad risk for human and air conditioning is also one of such technology which also has harmful effects on human body parts like respiratory system, skin, ears and brain etc. As much as air conditioners are a boon during extreme hot and humid weathers, long term exposure to them can have harmful effects on our health. The quantum of the health effects will depend upon the overuse/addiction of air conditioning and these effects can be summarized as:

Dehydration: Dehydration rates are known to be higher in rooms that are air-conditioned and one will usually end up dehydrated if the air conditioner sucks too much humidity from the room. The process of dehydration will be more when the temperature setting of air conditioner is low and one feel too cold to want to drink any water. Another unfortunate side effect of air-conditioned spaces, especially if they are not maintained properly, is susceptibility to headaches and migraines when the indoor air quality levels dip. In fact, dehydration is an often overlooked trigger for migraines.

Weaker Immunity: Air conditioning creates an artificial change in temperature which is unhealthy for human immunity causing weakening of immune system. People who frequently switch between extreme temperatures by staying inside home and office and later outside in scorching heat fall sick more frequently for no apparent reason. Those who spent a lot of time in an air conditioned environment become increasingly more intolerant of hot summer temperatures. The intolerance is mainly caused by the stress on the body from moving from a cool environment to the sweltering outdoor air. This intolerance of the heat has recently lead to an increase heat related deaths during heat waves.

Feeling constantly fatigued: When temperature of air conditioning is set very low, it causes internal shivering in a person’s body and when that individual works overtime it produces more heat causing constant fatigue which is the most crucial negative health effect of air conditioning. It is a well-known fact that muscles contract at cold temperatures. Too much exposure to the cold air can leave muscles stiff.

Sinusitis: According to the researchers, people who spend more than 4 hours in air conditioning environment are more likely to get diagnosed with sinusitis infections as the chilling cold air tend to harden or dry the mucous gland.

Dryness of eyes: Air conditioning environments tend to dry out eyes causing irritation of eyes; itchiness and tearing of eyes as the liquid of eyes get dry easily due to the cold temperature. Redness and swelling can also be caused due to over exposure to cold temperature. Sometimes it can get so bad, that vision is blurred. Air conditioning can also worsen eye conditions such as conjunctivitis and blepharitis. These problem seems to get worse when we spend long hours in an air-conditioned space.

Viral Infections: Air conditioning is a process in which there is no fresh air circulation rather the old air gets circulated over and over again transmitting bacteria and viruses of cold, flu from one individual to another. Another quite common negative health effect of air conditioning is getting viral infection which is ultimately due to weaker immunity. For people who are allergic to dust or fungi, air-borne infections can be a risk. Because air conditioners dry out nasal passages, they can cause irritation in mucus membranes and dry out the mucus. In the absence of adequate protective mucus, one can become more vulnerable to attack by viruses. In fact, notorious microbes like the bacteria that causes Legionnaires’ disease, for instance, thrive in artificial water supply systems, including those in air-conditioning units and systems. Air conditioning could make allergies and even asthma worse. While staying indoors in an air-conditioned space can be protective for some people who are sensitive to pollen or air pollutants, there are others who find their situation worsens with air conditioning. Upper respiratory symptoms in the eyes, nose, and throat tend to crop up much more in people who spend a lot of time in places that are air-conditioned than in those who spend time in non-air-conditioned places. These may include nasal blockage, a dry throat, or even rhinitis.

Skin dryness: Cold air environments can be a sole reason behind dry skin. Cold air produced by the air conditioners significantly dry out skin cells by damaging and creating fine lines making skin rough and dull. Long hours spent in an air conditioned room can cause skin to lose its moisture and leave it dry. This can affect scalp as well, leading to hair fall or dandruff.

Lethargy: A more comfortable environment may make us lazy and we may start avoiding going out in the sun. Any such thing may affect our physical fitness as well as our daily chores. Research indicates that people in air-conditioned buildings complain more of lethargy. In other words, the air-conditioning might be to blame for unexplained laziness and sluggishness. 

Noise: Lastly, ACs that makes a lot of noise can corrupt our idea of silence and peaceful work. Due to the constant humming of the machine, one can feel irritated or anxious due to the background noise. The constant noise generated by improperly fitted and less-efficient air conditioning systems may also potentially contribute to hearing damage. 

Up keeping of air conditioners

Dirty filters, un-cleaned ductwork and vents and poor overall maintenance can cause air conditioning system to release mold and other contaminants into the air we breathe. According to a research dirty filters allow pollen, pesticides and other outdoor pollutants to accumulate and enter our home. Such substances can adversely affect our health.  Here are some tips how and when to use air conditioning:

• Clean and/or replace unit's air filters according to the manufacturer's recommendation, or according to unit's clean filter notification.
• Have a yearly maintenance check performed by an expert service technician.
• Make sure home has adequate ventilation to help bring fresh air inside and reduce indoor contaminants.
• Turning off the system and opening the windows occasionally can help circulate the air for periods of time. 
• Turn the system off or down when no one is home and at night. This lowers the circulation of potentially harmful particles in air, if they exist.

Concluding remarks

While one can’t completely avoid the use of air conditioning particularly in humid summer as they are omnipresent in our daily lives, one should try and take frequent breaks. Warm up exercises and moisturizers can help too.  Setting the AC at an ideal temperature can also help for comfortability.  While working in an air conditioned environment, try to take a break every few hours and warm up or practice stretching exercises. If can’t get away from the air conditioner, try to make most of the use of fan, do not cool the empty rooms, set a moderate temperature and make sure to use enough moisturizers and oils for skin and hair.