Doctors are warning that air conditioning does more than cool a room. It can also dry out the skin, eyes, nose and throat, and in badly maintained units it may stir up dust, pollen and mould that can aggravate asthma.
The warning lands in the middle of a summer defined by relentless heatwaves and heavy use of cooling systems, when the appeal of air conditioning is obvious and immediate. For many people it is the quickest escape from the heat; for others, especially those with dry or sensitive skin, asthma or contact lenses, it can bring a different set of problems.
Dr Opel Baker said air conditioning removes humidity from the air, which helps people feel cooler but also increases water loss from the skin. That can show up as tightness, flaking, chapped lips or a flare-up of eczema. Baker said those already prone to dry or sensitive skin may find the effect even worse.
The same dry air can reach the eyes. Baker said air con may cause burning or stinging, and very rarely blurred vision. He said blinking a little more than usual can help settle the discomfort. Contact-lens wearers may notice the difference more sharply, because lenses can make eyes feel drier when the air is already stripped of moisture.
It does not stop there. Baker said the nose and throat are designed to stay moist, and when they dry out they become irritated. That can mean a sore throat, a blocked nose or a hoarse voice. Dr Lucy Hooper added that once the nose and throat dry out, mucus is harder to clear, which matters because mucus is part of the body’s immune defence.
There is also a maintenance problem that can turn a comfort into a trigger. Baker said poorly maintained air-conditioning units can increase the circulation of dust, pollen and mould, which can irritate the lungs and may trigger asthma. That is the sharpest reminder that the issue is not only the cold air itself, but the condition of the system pushing it around.
Another side effect can appear in the nose. Baker said the inside of the nose can dry out and crack, making nosebleeds more likely, especially if someone blows their nose too hard or picks it while it is already dry. The pattern is clear: air conditioning can be useful in the heat, but prolonged exposure can leave the body drier than many people expect. The practical question now is not whether it works, but how well it is maintained and how much drying a given person can tolerate before the comfort starts to cost more than it saves.
