Much of modern life is spent indoors, where air conditions continuously affect the skin. Both air conditioning and heating systems share one outcome: they lower ambient humidity.
As humidity drops, the moisture gradient between skin and air increases and evaporation accelerates — visible as rising TEWL. People spending long hours in air-conditioned offices or heated rooms often notice tighter-feeling skin by day's end.
Practical measures: support ambient humidity with a humidifier where possible, avoid direct airflow on the face, use a barrier-supported moisturiser during the day and ventilate regularly. Consult a physician for an approach suited to your skin type.