When summer arrives, it is easy to see how thermometers touch 40 ºC, or even before, as we are suffering right now. Here the air conditioning in the office, at home or even in the car becomes our best ally, since at first glance it is seen as an indispensable lifesaver. However, scientific literature tells us that it also has quite negative effects that go beyond the classic cold due to the extreme temperature changes that we face.
The most general effects. Centralized air conditioning systems are a problem, as has been documented by science itself, since it has been seen that they are direct sources of health problems if the indoor air quality is not optimal. And the consequences are quite clear: dry eyes, headache, fatigue and difficulty concentrating.
With concrete data. A study published in 2023 with 400 adults in India compared people who were exposed to air conditioning versus those who used natural ventilation in their daily lives. What was seen is that users who were regularly air conditioned suffered many more cases of dry eyes, pharyngitis and nasal congestion than those who were in more natural conditions.
But in addition, medical tests showed that lung function was significantly lower in people under constant air conditioning. Specifically, 35% of them developed rhinitis, compared to only 9% in natural ventilation environments.
The consequences. This impact on health translates into lost days, since people who work with air conditioning missed an average of 22 days a year, compared to just 13-15 days for those in offices without artificial air conditioning.
Muscle pain. Something that I have personally heard a lot, especially from older people, is that air conditioning makes them have severe ‘bone pain’, especially if it hits them directly. And the reality is that direct cold triggers a defense mechanism in the body to increase the temperature and maintain it at 36-37 ºC through a contraction of the muscles.
So, if the exposure of the muscle to the cold of the air conditioning produces a muscle contraction, it means that those people who set the air conditioning to 18 °C see their maximum grip strength decrease by 20% and the speed of development of that force plummets by 50%.
In the cervical This is where it has been clearly seen that superficial cooling increases the tension of the sternocleidomastoid muscle, which explains the classic torticollis. But they even explain the facial paralysis that occurs due to exposure to these jets of frozen air and that we colloquially call ‘it has given him a wind’.
Pollution. If the air conditioner cools, but its filters are not maintained, the device becomes a diffuser of pathogens. This is especially important in hospital centers where the prevalence of nosocomial diseases can increase. But in Spain the most serious danger has a name and surname: Legionella pneumophila.
This is a bacteria that finds its perfect ecosystem in cooling towers and air conditioning generators, causing legionellosis, which is a very important atypical pneumonia condition.
The protective character. If the air conditioning has high-efficiency filters, the picture changes radically by eliminating these pathogens. But the most interesting point is in a 2017 study involving 200 participants in Taipei that showed that air filtration improves cardiovascular health by reducing fine particles and volatile organic compounds from the outside.
The ideal temperature. Knowing all this, what is the balance point? The consensus of experts and clinical studies indicates that the thermostat should be between 24 °C and 25 °C. Medical evidence indicates that going below 20°C guarantees the appearance of significant musculoskeletal problems and would also irritate the bronchial mucosa, which would be a major problem for patients who have lung disease.
And if you want to have a refrigerator at home below 17ºC, the clinical literature points to significant exposure to respiratory and also joint problems.
Images | lifeforstock in Magnific
In | We have a problem in Europe with air conditioning. There are reasons to use it little, but when the heat hits everything changes
