One simple habit during flights can help avoid major health risks later, finds research

Air travel has become routine for millions of people, whether for work, family visits, or vacations. Yet long hours spent in a pressurised cabin bring their own set of health challenges—ranging from fatigue and dehydration to a higher risk of exposure to airborne infections. While airlines have upgraded filtration systems to improve safety, experts say that small personal choices during a flight can also make a big difference. One of the most overlooked habits is the use of the overhead air vent.

What research says about cabin air quality

A 2022 randomized controlled trial published in Environmental Research examined how cabin occupancy and air circulation affect passengers. The findings showed that when cabins were full and ventilation was limited, travelers experienced higher stress levels, greater fatigue, and more discomfort. This study highlights the role of airflow in ensuring passenger health, particularly on crowded flights.

Modern aircraft are equipped with advanced air systems that refresh cabin air 20 to 30 times every hour. According to the International Air Transport Association (IATA), this means cabin air is replaced every two to three minutes—far more frequently than in most indoor spaces. These systems also use HEPA filters that capture over 99 percent of harmful particles, combining fresh and filtered air for safer breathing conditions.


Why turning off vent can increase risks

Shutting the air vent stops the protective stream of filtered air from flowing around your seat. Without that airflow, airborne particles from nearby passengers—such as germs spread by coughs or sneezes—can linger longer in your breathing zone. This creates a higher chance of exposure to illnesses, especially in crowded conditions. The Environmental Research study further underlined that reduced airflow combined with high passenger numbers led to noticeable drops in overall comfort.

Managing comfort during flights
Airplane cabins are known for their dry environment, with humidity levels often dropping below 20 percent. Many travelers believe turning off the vent will reduce dryness, but this does not make a difference. The cabin air remains dry regardless of vent usage. Instead, proper hydration, moisturisers, lip balm, and eye drops are more effective ways to ease dryness.


At the same time, the overhead vent helps regulate personal comfort by cooling down the space around your seat. A gentle stream of air can ease stuffiness and reduce heat buildup. Adjusting the vent to a low or medium setting and angling it toward your chest or above your head—rather than directly at your face—offers a balance of comfort and protection.

Experts recommend not switching off the overhead vent completely. Instead, passengers should learn to adjust it smartly—using clothing layers, scarves, or blankets to stay warm while keeping airflow steady. This small step helps maintain fresher air, lowers the risk of airborne exposure, and provides better temperature control throughout the journey.