It’s almost time to get on your planes, and the last thing you want is to be sick for the holidays. You might think the recirculated air is a risk to your health, but it’s actually the very dry cabin air and fatigue that cause most upper respiratory infections. Not to mention germs and bacteria all over the plane. Here are some tips from the LA County Department of Public Health. Feel free to ignore all the tips on your flight back to legitimately call in sick after the holidays.