Got a fever? Best to cool it on the pills.

Thermometer by Andres Rueda, pills by Tyler Sparks, collaging by yours truly.

It’s time to wake up and smell the cough syrup, people; cold and flu season is here.* Soon everyone you know will be hacking and sneezing and generally assaulting you with their horrible germs. Illness is inevitable. You will get sick. And what to do then? If you’re like me, you probably gave up on store bought cold remedies ages ago. What’s the point? They merely suppress symptoms in exchange for other side effects. All you need to battle a run-of-the-mill virus is rest, fluids and maybe some over-the-counter pain reliever (Advil or Tylenol or the like) to reduce the fever, which is really the bulk of what’s making you feel so crappy. Right? After all, blowing your nose is just inconvenient, while a fever is incapacitating.

Well, you may want to reconsider even such modest medicating, because fever does more than just make you miserable, it also restores your health. This isn’t exactly news. It’s well known that an increase in body temperature can slow down bacteria and other microscopic invaders while the immune system mobilizes against them. Fever can even help accelerate the clearing of the parasite that causes malaria. In addition to thwarting cooties, fever can also improve the body’s pathogen fighting mechanisms. A recent study in the Journal of Leukocyte Biology found that a 2 degree centigrade increase in body temperature in mice resulted in improved differentiation of the lymphocyte CD8+ T – one of the cells involved in the immune response to viruses. While it may be detrimental to your performance of normal daily tasks (like staying awake and sitting upright), a fever actually makes your immune system more efficient.

So why are we still so quick to swallow fever-reducing pills? Certainly part of it is comfort (nobody likes feeling awful), but another problem is the perception the fevers are dangerous. While fever can be a part of serious illness, many high fevers result from minor ailments (and conversely, serious illness may present with only a mild fever). 103°F is a figure frequently given as an appropriate panic point (i.e., when call a doctor). But haven’t you had a 104° fever at some point in your life and not sought medical attention? And you were fine, right? The fever didn’t keep rising exponentially until it broke the thermometer and literally cooked your brain? Same here. The reason for concern over high fevers has more to do with possible complications of elevated body temperature than the fever itself. Dehydration, seizures – these are issues that might benefit from the presence of health care professionals.

“But can’t a fever be life-threatening?” you ask, “I’m sure I saw it on television once.” You are perhaps confusing cold/flu-induced fevers with something like heatstroke. Heatstroke occurs when the body has been pushed by strenuous exercise and ridiculously hot weather (think football practice in August) to the point where standard mechanisms for thermoregulation (sweating, dilating blood vessels, etc.) aren’t doing the trick anymore. The individual’s temperature rises not as defensive response to pathogens, but because the body has lost control of its internal environment. It’s potentially fatal, and gives one a sense of what reptiles have to worry about daily.

And while we’re empathizing with snakes and lizards, it’s worth noting that ectothermic animals (often described as “cold-blooded”†) also respond to infection with fever. How? While they can’t regulate their body temperatures internally like we do, reptiles can raise or lower their temperature behaviorally – for instance, by choosing a sunnier or shadier rock to lounge on. Research has shown that reptiles injected with bacteria will aim for a slightly higher temperature than non-infected control animals. Basically, when lizards get the sniffles, they cope with a behaviorally-induced fever rather than a bottle of ibuprofen.

The fact that even reptiles exhibit a fever response tells us that it’s a pretty old strategy for fighting infection. It’s certainly been around longer than NyQuil, echinacea, and chicken soup. While nothing cures the common cold, toughing out one its more uncomfortable symptoms is more likely to speed the healing process than your favorite home remedy.

Does this mean you have to forgo the pills entirely? Hey, I’m not your mom. Do whatever you like. There are plenty of good reasons for attempting to pull yourself together for a few hours despite being sick (birthdays, rock concerts, possibly even jobs). You just need to accept that you’re in for a certain volume of misery regardless. The only real decision is whether to spread the suffering out over more days, or just get it over with already.

* Well, at least here on the northern side of the Equator. I’m guessing that might not be the case elsewhere. Feel free to tune this one out for now, Southern Hemisphere.

† Their blood isn’t actually cold, they just have to stay warm behaviorally (by basking in the sun and that sort of thing) rather than with the fancy metabolic tricks of endotherms like ourselves.