Why you should never turn off the air conditioning above your seat during a flight

The next time you go to turn off the ventilation above your seat on an airplane,you might want to reconsider.

Using that tiny vent can actually work to your advantage, as it can help you avoid contact with certain microorganisms that can get you sick during a flight.
Travel + Leisure spoke to Dr. Mark Gendreau an expert on the spread of infectious diseases associated with air travel He said Airborne viruses like tuberculosis and measles, are transmitted by tiny droplet nuclei that can hang in the air for up to five hours.

He says these droplets can't in fact reach you if the air con is on, because a barrier has been formed around you which prevents this.

“Ventilation on airplanes has gotten a bad reputation, but it’s completely unfounded,”
“The flow pattern of air on an aircraft doesn’t necessarily work front to back, or back to front. It’s actually compartmentalized into various sections on the aircraft,” Gendreau said.
“As a rule of thumb, the air that you’re typically breathing and exposed to is usually anywhere from two to five rows surrounding your seat,” he added.“For airborne viruses, it is incredibly important to ventilate, since ventilation becomes your main means of control besides isolating the affected person,” Gendreau said.

By using the vent and turning it on medium or low, you can create an invisible air barrier around you that creates turbulence — simultaneously blocking these particles and forcing them to the ground faster.