If you’re a frequent flyer, you might want to get your head checked. That’s because, according to a recent report in the Wall Street Journal, Airbus A320s — used by the three largest airlines in the U.S. — have a tendency to leak carbon monoxide and unspecified quantities of neurotoxins into the cabin air.

While “bleed air” has been a problem for a while, the Wall Street Journal reports that bleed-air events are increasing in frequency, and that their impact is becoming more disastrous. For example, the number of fume incidents saw a combined 660 percent increase over the past eight years, and passengers and flight attendants alike have reported severe brain injury from fumes entering the cabin.

How do you know if you’re about to be hit by these fumes? While some fume events produce smoke, most don’t, meaning you’re going to have to rely on your nose to determine if your life is about to change for the worse.

Those who have experienced them describe the smell of the fumes as something between “wet dog,” “nail polish” and “Cheetos.” If you’re on a flight and start smelling that, well, there’s not really much you can do apart from trying to breathe through your shirt to minimize the amount of particulate you’re inhaling. It’s not much, but what else can you do — open the window?

@dailymail Jet fuel leaks are causing permanent damage Credit: Storyful (multiple users) #airplane #flight#usa♬ original sound - Daily Mail