I have faith in few medical tricks. I’ve never found the “press your thumb to the roof of your mouth” thing for brain freezes to be effective, nor has ginger ale ever done much to cure my stomach troubles. But for almost any infliction that hits in the car — primarily headaches, stomach aches and nausea — rolling down the windows has absolutely never failed me. It’s a method I still see my mom apply to my eight-year-old niece, and one I’ll suggest in the back of a car with a queasy, too-drunk friend. Maybe it doesn’t stop someone from throwing up in all cases, but at least the fresh air and open window allow for a better venue to do so.
That said, though I know deep in my core that rolling down the window is an effective nausea treatment, I know nothing of why it works. Would standing in front of a fan do the same thing? What if I just ran really fast, simulating the experience of a nice, cool breeze?
I’m not the first to ponder the universal rule of the open window. It’s been a topic of discussion on r/ExplainLikeIm5, r/AskScience, and as with all stupid questions that probably don’t even need answering, Quora.
The answers given on r/ExplainLikeIm5 are mostly bunk — the whole thread basically got hijacked by someone else asking why breathing in through your nose and out through your mouth helps with car sickness. Apparently it has something to do with the fact that our nose serves as a better air filter and temperature regulator, and that our mouth allows more used-up air to be expelled than our nose. On Quora, someone answered in all caps: “JON, I HESITATE TO ANSWER YOUR QUESTION AS THE LAST TIME I ANSWERED A QUESTION ON CAR SICKNESS, IT WAS REJECTED. GETTING A PERSON TO FRESH AIR IS NOT A NEW CONCEPT IN MEDICAL CARE. IT IS A TECHNIQUE USED FOR ANY NUMBER OF THINGS, EVEN FOR ANIMALS.”
While this is not all that helpful, that person is right in saying it’s not a new concept in medical care. In far clearer terms, members of r/AskScience offered a similar explanation. When treating motion sickness — which can broadly include all those types of nausea and headaches that occur in a moving car — several reputable medical guides do offer opening a window or blasting some A/C as a recommendation. As a moderator for r/AskScience explained on the sub 10 years ago, studies have found that breezes of any variety — whether from nature, a fan or an A/C — are effective in reducing feelings of nausea. Such studies, however, haven’t exactly explained why they’re effective, just that they are.
But when we dial in on the mechanisms of motion sickness as the usual culprit for nausea in the car, we get a better idea. As Robert Glatter, an emergency physician at Lenox Hill Hospital in New York City, told LiveScience last month, motion sickness and nausea both cause our core body temperatures to drop. Our brain, though, tries to regulate this drop in temp, and in turn, makes us feel hot and sweaty instead. Getting an outside source of cool helps balance everything out.
In the car, opening a window, rather than just blasting the A/C and closing our eyes, can help for another reason, too. If we stick our head out the window, we’re better able to see the motion of the car and our relationship to the space around us. Often, motion sickness is itself the result of our brain struggling to comprehend this movement, but sticking our head out the window allows us to make better sense of how we’re moving.
So, the general idea is that cold air of any sort helps our body regulate its temperature and therefore ease some of the nausea, but also that the open window helps solve some of the causes of motion sickness, too. When you’re drunk, motion sickness might not be as much of a cause of your nausea, but the cool air helps the same. More importantly, the open window offers you ample opportunity to throw up outside the car. Depending on the condition of your car and the air around you, rolling down the window rather than using the A/C might also help provide a sense of “freshness” that tricks us into feeling less disgusting.
Personally speaking, I like to think that opening a window and sticking my head out helps because it reminds me of what my mom would make me do whenever I was carsick. I probably had countless instances of throwing up all over myself and my car seat as a child, despite the open window, but all I can remember now is how my mom tried to comfort me from the driver’s seat by rolling down the glass. Even if that doesn’t cure my nausea, the memory makes me feel a little better.