As temperatures continue to soar during summer, air conditioners have become essential in many households. Yet despite their widespread use, concerns about sleeping in air-conditioned rooms persist — especially the belief that AC exposure weakens the body’s “immunity power.”
According to Dr Manas Mengar, this idea is largely a myth.“Air conditioning itself does not weaken immunity,” says Dr Mengar. “From a pulmonologist’s perspective, the bigger concern is how the AC is being used rather than the cooling itself.”
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.
He explains that good sleep, comfortable room temperatures, and proper ventilation can actually support immune health and physical recovery.
Why people feel sick after sleeping in AC rooms
Many people complain of waking up with a sore throat, dry nose, sinus congestion, coughing, or frequent sneezing after spending long hours in air-conditioned environments. However, Dr Mengar says these symptoms are usually linked to dry indoor air and poor AC hygiene, not reduced immunity.
“Air conditioners can reduce indoor humidity, which dries out the nose, throat, and airways,” he explains. “These moist surfaces normally act as a natural protective barrier against dust, viruses, and pollutants. When they dry out, irritation increases.”
Another major factor is poor maintenance. “Dirty AC filters can circulate dust mites, mould spores, bacteria, and allergens,” says Dr Mengar. “This may trigger sneezing, coughing, sinus congestion, or asthma flare-ups.”
According to him, many people mistake this airway irritation for an actual cold or infection. “In many cases, it is allergy-related inflammation or dryness rather than a true infection,” he says.
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Can sudden temperature changes affect the body?
Doctors also point out that moving repeatedly between extreme outdoor heat and freezing indoor temperatures can place stress on the respiratory system.
“Sudden temperature shifts can irritate the respiratory tract, especially in people with asthma, allergic rhinitis, sinusitis, or sensitive airways,” says Dr Mengar.
Walking from intense heat into an extremely cold room may trigger nasal congestion, throat irritation, coughing, or breathing discomfort.
However, he clarifies that temperature change itself does not directly cause infections.
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“Viruses and bacteria cause infections,” he explains. “But abrupt temperature swings can temporarily irritate the airways and reduce comfort, especially if hydration and sleep quality are already poor.”
Does AC affect sleep quality?
According to Dr Mengar, sleeping in a comfortably cool room may actually improve sleep quality and support better recovery.
“In fact, uninterrupted sleep in a comfortably cool room can help the body recover better and maintain healthy immune responses,” he says.
Problems arise when temperatures are set excessively low for long durations or when airflow directly hits the face or chest throughout the night.
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The healthiest way to use AC while sleeping
Experts say the key lies in balanced and moderate AC usage.
“The healthiest approach is comfortable cooling — not turning the room into a refrigerator,” says Dr Mengar.
For most adults, he recommends maintaining bedroom temperatures around 24–26°C depending on individual comfort levels.
He also suggests several habits to reduce AC-related discomfort:
- Clean AC filters regularly
- Maintain indoor humidity to prevent excessive dryness
- Ensure some ventilation or fresh air circulation
- Stay hydrated during hot weather
- Avoid direct cold airflow on the face or chest while sleeping
“A good AC setup should improve sleep quality, not disturb it,” says Dr Mengar. “From a lung health perspective, comfort, clean air, and proper maintenance matter far more than the AC itself.”
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DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.
