How to Avoid Getting Sick on a Plane

Why Planes Make People Sick

Let's clear up the biggest misconception: it's usually not the recirculated air that gets you sick. Modern aircraft use HEPA filters that capture 99.97% of airborne particles, including viruses and bacteria. The filtration system is actually cleaner than most office buildings.

The real culprits are contaminated surfaces and close proximity to sick passengers. You touch a germ-covered tray table, then rub your eye, and suddenly you've given a cold virus a direct path into your body. That's how most in-flight infections happen.

The Dirtiest Spots on a Plane

Studies testing aircraft surfaces have consistently found these areas carry the most bacteria:

• Tray tables -- The single dirtiest surface on the plane. They're used as changing tables, tissue holders, and food surfaces between cleanings. Some tests found more bacteria per square inch than airplane toilet seats.
• Seatbelt buckles -- Everyone touches them, and they rarely get wiped down
• Armrests -- Shared surfaces touched by multiple passengers daily
• Overhead air vents -- Touched frequently by every occupant
• Lavatory door handles and faucets -- Obvious germ hotspots
• Seat-back pockets -- People stuff used tissues, dirty diapers, and food wrappers in these. Don't put anything in them that touches your face later.

Seat Selection Matters

Research from multiple studies shows that where you sit affects your exposure to germs:

Window seats are safest. You have contact with fewer passengers and nobody walks past you to reach the bathroom. An Emory University study found that passengers in window seats had the least contact with other travelers.

Aisle seats are riskiest. Everyone walking to the bathroom passes by you, brushing your armrest or headrest. Flight attendants, other passengers, and their germs all parade past your seat. The study found aisle seat passengers had significantly more contact with other people.

Middle-of-the-plane seats are better than seats near the bathrooms, where passengers congregate and wait.

Your In-Flight Defense Kit

Pack these items and you'll dramatically reduce your risk:

Sanitizing Wipes (Essential)

The single most important thing you can bring. As soon as you sit down, wipe everything:

• Tray table (both sides)
• Armrests
• Seatbelt buckle
• Overhead air vent knob
• Window shade handle
• Headrest
• Entertainment screen (if touching it)

This takes 30 seconds and eliminates the vast majority of surface germs. Use disinfecting wipes (Clorox, Lysol), not just baby wipes which don't kill germs.

Hand Sanitizer

At least 60% alcohol content, as recommended by the CDC. Use it after touching common surfaces, before eating, and after using the lavatory. Soap and water is better when available, but sanitizer works well in between.

Tissues

For coughs, sneezes, and touching surfaces you'd rather not touch directly.

Hydration: Your Immune System's Best Friend

Aircraft cabin humidity runs 10-20%, compared to 30-65% in most homes. This dry air does two things that increase illness risk:

• Dries out your nasal passages and throat, weakening your first line of defense against viruses
• Dehydrates you, which reduces overall immune function

What to do:

• Drink water aggressively -- 8 ounces for every hour of flight time is a good target
• Bring your own water bottle -- fill it after security
• Avoid alcohol and caffeine -- both dehydrate you further
• Use saline nasal spray -- keeps nasal membranes moist and functional
• Skip airplane tap water -- stick with bottled water. EPA studies have found bacteria in airplane water tank systems.

The Air Vent Trick

That overhead air vent isn't just for comfort. Using it correctly creates a downward flow of filtered air around your seat, which helps deflect airborne particles away from you.

• Turn it on to medium flow
• Angle it so the air flows just in front of your face
• The downward airflow creates a barrier that pushes germs away from your breathing zone

Don't turn it off to stay warm. The airflow is your friend.

Before Your Flight

Your immune system's condition before you board matters more than anything you do on the plane:

• Sleep well the night before -- sleep deprivation crushes immune function. Studies show people getting less than 7 hours of sleep are 3x more likely to catch a cold
• Stay current on vaccinations -- flu shot, COVID boosters, and RSV vaccines for eligible travelers
• Eat well and exercise in the days leading up to travel
• Don't fly if you're already sick -- the dry cabin air and pressure changes will make it worse, and you'll spread it to others

During the Flight

Keep Your Hands Away From Your Face

This is the single hardest habit to break and the most important. Viruses enter your body through your eyes, nose, and mouth. Every time you touch a contaminated surface and then touch your face, you're potentially infecting yourself.

The average person touches their face 16-23 times per hour. On a plane full of germy surfaces, that's a lot of opportunities for infection.

Eat Smart

• Use hand sanitizer before eating anything
• Use your own utensils if possible
• Don't eat food that's been sitting on the tray table without a barrier
• Skip the in-flight magazine if you're going to eat afterward -- it's been touched by dozens of passengers

Consider a Mask

A high-quality mask (N95 or KN95) provides genuine protection against airborne pathogens. It's especially worth considering on long flights, during cold and flu season, or if you have a compromised immune system. It's not required, but it works.

After the Flight

• Wash your hands thoroughly as soon as possible
• Change clothes if you've been on a long flight
• Stay hydrated for the next 24 hours
• Get good sleep to let your immune system recover

What Doesn't Actually Help

A few commonly repeated tips that aren't supported by evidence:

• Vitamin C megadoses right before a flight -- the evidence is mixed at best. Regular intake over time matters more than a pre-flight dose
• Holding your breath when someone coughs -- impractical and unnecessary with cabin air filtration
• Avoiding airplane food entirely -- airline food isn't inherently germy; it's the surfaces you eat off of that matter