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In January 2011, I got iced into my parents’ house in suburban Atlanta for what felt like 15 years, but was actually one week. The metro area was paralyzed by a storm unprecedented in its recorded history: A rare heavy snow was immediately followed by a stretch of finger-numbing cold. The combination plunged the area into a cycle of modest daytime melts and overnight freezes that left millions of people stuck under a self-renewing sheet of ice for days.

Because of the region’s hilly terrain and very limited winter-weather infrastructure, not only was no one ever going to come salt our roads, but it was unclear whether we could even call an ambulance. We were several miles from the nearest grocery store.

Frigid days ticked by, and the meteorologists on the evening news had nothing encouraging to say. What started as a fun respite from normal responsibilities turned into a familial prison, confining me, my retired parents, my little brother, and a rambunctious English bulldog to endless bickering over what we’d have for dinner and what we’d watch on TV. Outside, people occasionally passed on four-wheelers that they had apparently been hiding in their garages. I watched someone slide down our street on a boogie board, destination unknown.

On the sixth day, sick of looking at one another and eating canned goods, my family made our first attempt at escape, which would involve coaxing my dad’s midsize sedan up our sloped, frozen driveway. We wanted tacos. Getting them—two days later, when things finally loosened up—cost $400 for the tire we shredded on the ill-fated first try, plus the price of the tacos.

Bad ideas aside, we were lucky: We had food and shelter, and our jobs weren’t in danger because we couldn’t leave the house, which not everyone has in emergency weather situations. But as temperatures across the Midwest drop to a couple dozen degrees below zero this week, millions of people become potential victims of the same phenomenon that inspired three otherwise intelligent people (my mom, the smartest of the bunch, sat out) to flush several hundred dollars down the toilet in the obviously doomed pursuit of carne asada: cabin fever.

Like many psychological phenomena, cabin fever exists in both a cultural and a clinical sense. In regular conversation, the term is something of a catch-all for the boredom and restlessness brought about by being inside for too long. To doctors, cabin fever itself isn’t a diagnosable disorder, but instead the presence of a number of overlapping psychological symptoms that can have real impacts on a person’s behavior and well-being. Usually those symptoms have to hang around longer than the average blizzard or cold spell to start causing real health problems. Still, if you’ve ever snapped at a spouse or felt yourself sinking into depression after a couple of days stuck indoors, you know how quickly they can emerge.

Cabin fever as a specific phenomenon hasn’t been subject to much research, but its elements have been well studied by psychologists. A landmark 1984 study by researchers in Minnesota (where people have some experience with cold weather) found that although “cabin fever” means slightly different things to different people, it’s most often characterized by combinations of boredom, anxiety, irritability, and restlessness. Even for people in places where periods of extreme cold are common, being taken out of your daily routine, cooped up in your house, and significantly restricted in your choices and activities is, in essence, stressful.

How the body reacts to that stress seems to be key to how cabin fever rears its ugly head. In the years since I saw people pulling random sporting goods out of storage in Atlanta, I’ve also watched people ski down New York City’s streets during snowstorms and concoct ill-conceived makeshift transportation devices involving sheets of cardboard, garbage-can lids, and whatever else is lying around. Granted, some people might just find this fun, but many with cabin fever are very intent on getting out. That’s true even when they don’t really need to—we didn’t need those tacos—which may be a form of fight-or-flight instinct, clinically referred to as a cortisol stress response. You can’t exactly throw a punch at Mother Nature, so instead, you might try to escape the conditions that have you climbing the walls.

Cortisol, a hormone released in the body when a person is stressed out, can have a variety of effects: increased blood pressure, decreased immune-system efficiency, and problems with memory and learning. The hormone gets deployed even against short-term and situational stimuli, such as traffic jams, and multiple studies have found that average seasonal cortisol levels are highest in winter. Confinement—even if other people are present—can be very stressful, too. If you have kids, good luck finding an indoor way to burn through the energy they’d usually use at school or the park. In that way, cabin fever is something of a perfect storm for a hormonal stress response to things you might not even recognize as stressors. And being snowed in alone isn’t necessarily any better: Feeling lonely is also bad for your health.

The good news for people feeling weather-induced cabin fever is that weather changes quickly: Temperatures in the Midwest are already slated to return to normal in the next few days. Plus, according to the 1984 study, understanding cabin fever can help moderate your responses to it. And even if you need a new tire or scrape your knee slipping on ice, most healthy people will withstand a couple of days indoors without lasting problems.

Just be careful of winter’s most expensive potential health outcome: children. Research is split over whether “baby booms” really happen in response to specific winter storms, but the most common birthdays are disproportionately crowded into the part of the calendar that comes nine months after winter.

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