Hi. I have just completed a stint of night shifts – twelve in the last fourteen days – and I feel like a moldy, rotted potato.

As I write this, I’m trying to “flip back to days” for a regular day shift tomorrow, as the cruel scheduling gods have elected to grant me one day of work during normal people hours (albeit on a Saturday) before switching back to a third week of uninterrupted nights.

This is presumably to so thoroughly mess up my circadian rhythm that I no longer realize night shifts are during hours when the sun is below the horizon.

A prolonged stretch of nights does terrible things to your body and mind. For starters, your ability to resist junk food goes precisely to zero. If you leave a Snickers bar unattended at four in the morning, I will eat it. That bag of Doritos you opened around midnight and said, “this is for sharing?” It’s mine now.

Also, it is gone.

I experience the same sense of helpless animalism as my dog when he howls at the noon church bells: he doesn’t know why he’s howling, just that he has no ability to resist whatever DNA program activating whenever a giant bell tolls.

After a prolonged series of nights, I start to resemble the Pillsbury Doughboy and, partly because of the sharp uptick in Doritos and Cookies Intake, feel the same way.

If you are a normal human being and don’t routinely work at night, you also don’t know about the Cortisol Low. Around 4 am, almost universally, every night shifter gets freezing cold and feels like complete shit for about ninety minutes. This has to do with the natural variation of your body’s stress hormone, cortisol. In caveman (and current) times, 4AM was generally a pretty safe time when even the tigers and lions and other man-eating creatures were asleep. Thus, it was when our body let up a little on the fight-or-flight stuff, since people were also asleep.

Unfortunately, we Nights Watch members are awake during this time, a fact that our dumb adrenal glands do not respect. Thus we shiver between 4 and 6 AM. If you’ve ever had the shakes with a flu, that’s kind of what it feels like. It’s exactly as miserable as it sounds.

Another side effect of night shift life is that sleep after work is not really something that can be delayed. Think about your normal human routine: You get off work, go home or to the gym, cook some dinner, watch some TV, catch up with friends, grab a drink. By the time you actually get in bed, it’s probably been a few hours since you left your office, right?

After a night shift, you are not just sleepy. Calling your state of mind “sleepy” gives short shrift to the driving, overwhelming NEED to crash. It is an absolute, pure, biological imperative.

Last week, I worked from 8pm to 4am, and didn’t have my next shift until 8pm the following night. I had grand plans to sleep from about 5 to 10, get up and run some errands, grab some sunshine, and then go back to sleep for a pre-shift nap.

I ended up unconscious for eleven hours straight and accomplishing none of those things. ELEVEN HOURS. IN THE MIDDLE OF THE DAY. The only people over 18 capable of doing this usually have either a brain tumor or severe narcolepsy.

After a certain number of consecutive nights – I currently have this pegged at three – your relationship to sleep changes. Instead of feeling overwhelmingly tired during and after your shift, you just become delirious the entire time. Everyone manifests this differently. I tend to become inappropriately giggly – last night I started laughing during a prolonged discussion about various descriptors for poop with a severely constipated patient – and a bit inattentive.

This morning, my phone rang four separate times with a consultant who was looking for me. I stared at it each time, watched it ring, and did nothing. It wasn’t that I was ignoring the phone. I just couldn’t make the necessary connection between the problem (a phone is ringing) and the solution (answer the phone, it’s yours).

The fourth time, my attending said, “are you going to answer that?” and it finally dawned on me that the ringing was, in fact, coming from my phone.

I picked up and stupidly answered, “Yeah?” The consultant hung up.

Sign out to the oncoming resident a few minutes later: “The ortho guy is going to call about bed 19; he’s going to be kind of mad. Sorry in advance.”