In the Israeli summer, the air conditioner becomes almost part of the daily routine. At home, in the car, in the office, and in public spaces. Alongside the obvious comfort, quite a few people report dryness, a sore throat, eye irritation, or a feeling of "catching a cold" after a prolonged stay in an air-conditioned room. These feelings are real, but the reason for them is not always an infectious disease.
Does an air conditioner really cause illness?
An air conditioner does not cause the flu or a cold, because such diseases are caused by viruses and not by cold or low temperatures. What does happen is that indoor air-conditioned conditions can affect the mucous membranes of the nose, throat, and eyes, thereby creating a feeling of discomfort that resembles "the beginning of an illness."
What happens to the body in air-conditioned air?
The mucous membranes in the respiratory tract are the body's first line of defense. When the air is dry, the mucous membranes may lose some of their natural moisture, and then dryness, burning, a feeling of irritation, and sometimes also a light cough appear. A recent review published in 2024 in the journal International Journal of Hygiene and Environmental Health found that low humidity inside buildings is associated with an increase in eye and respiratory symptoms, and also with a decrease in the natural clearing ability of the airways.
In simple words: The air conditioner does not "invent" a disease, but it certainly changes the conditions in which the body needs to function. When the air is cold and dry over time, especially in a closed room or a well-conditioned office, the body feels it first through dryness and sensitivity, and only afterwards through the general feeling.
Why is it felt more in the summer?
The summer creates a problematic combination: Outside it is very hot, and inside it is cold and dry. The frequent transition between extreme heat and the cold of the air conditioner creates a load on the body's regulation systems, and at the same time may increase a feeling of discomfort in the eyes, nose, and throat. Reviews on indoor air quality emphasize that prolonged exposure to low humidity and an air-conditioned environment is associated with a feeling of "dry air" and more common complaints in closed spaces.
The research literature does not say that an air conditioner causes infections, but it does show a consistent link between dry air and symptoms of irritation. A review from 2021 found that exposure to dry air inside buildings, especially during heating seasons, was associated with dryness and irritation in the upper respiratory tract and skin. Another review from 2024 reinforced this finding and emphasized that low humidity in offices and closed spaces increases symptoms in the eyes and airways.
It is important to be precise here as well that in most cases this is a physiological response of the mucous membranes to the environment, and not a disease in itself. Therefore, many people feel "like they are sick," but in practice suffer from dryness, irritation, or environmental sensitivity.
Common myths about air conditioners
"Air conditioner causes the flu"
Incorrect. The flu is caused by viruses only. An air conditioner can affect the body's sensation, but does not create the disease itself.
"You should not sleep with an air conditioner"
Inaccurate. It is certainly possible to sleep with an air conditioner, as long as the temperature is balanced and the air is not too cold or too direct. The problem is not the use itself, but the conditions it creates.
"The air conditioner dries out the body"
The air conditioner mainly dries out the air. This dryness is what can cause a feeling of dryness in the mucous membranes, eyes, and throat.
"If you don't feel well – It is surely because of the air conditioner"
Not necessarily. Sometimes it is a real viral infection, and sometimes it is dryness, an allergy, or prolonged exposure to a closed space. The difference is important, because it also changes the correct response.
How to use an air conditioner correctly?
The recommendation is not to give up on the air conditioner, but to use it wisely: To keep a moderate temperature, avoid a direct flow of air to the face over time, ventilate the room from time to time, drink enough during the day, and take care of periodic cleaning of the filters. Indoor air quality studies emphasize that maintenance and ventilation are a significant part of reducing the feeling of dryness and irritation in air-conditioned spaces.
An air conditioner is not an enemy of health, but a vital tool in the Israeli summer. The problem begins when the air becomes too dry, when there is not enough ventilation, or when the cold air meets a tired body that has already been working long hours in hot conditions. In most cases, the sensations attributed to the air conditioner are not an "illness" but the body's reaction to the environment it is in.
Dr. Kay Alkra is a family physician, Maccabi Healthcare Services Northern District