by chelsea schuyler

How Does the Body Do Hot?

Have you ever wondered how your body makes you hotter when you have a fever?

As a privileged first worlder, I know how to make something hot, and that’s by turning on my fire device (oven, lighter, camp stove) or cranking the thermostat. I’m pretty confident those are the only ways, though I have heard a cute tribal story about sticks.

Yet without any of those conveniences, how does the body heat up on its own?

Turns out, the body goes for the thermostat option. It’s called the hypothalamus, which is a little nubbin at the base of your brain. I’ve included a picture but really, since when have brain-location-pictures ever helped anyone? They’re all just globular curves with a highlighted bit. Just imagine a box of neurons somewhere that complain all day long about the temperature outside.

The hypothalamus is the one that decides whether to engage in making you colder or hotter – called thermoregulation. This is to prevent hyperthermia or hypothermia, which, after a long enough time, are both referred to as “incompatible with life.” Which I love. Like saying, “Oh, sorry life, you and me, we’re just not compatible. We like smoking hellscapes and frozen ice worlds, but you insist on ‘living’.”

(Hypo- and hyperthermia are convinced there are other fish in the sea, and will probably soon discover love in the tardigrade. The microscopic moss piglet, aka water bear, aka tardigrade, can survive in temperatures pushing -459°F; -273°C otherwise known as absolute zero! …Not actually a fish. Stay with me here.)

How Does the Hypothalamus Work?

Before we get into the heat overload of fever, let’s talk about how it works normally. The thermostat in your house works because magic. In your body however, it gets all biology-test-complicated.

Remember the Kreb’s Cycle? Citric Acid Cycle? No one does. Basically, picture a series of Dr. Seuss machines all working in your body, crunching, breaking down, and reforming food behind colorful curtains. Out pops energy on the other side. All those old school machines – that room would get pretty hot. When you metabolize food, the series of processes releases heat as a byproduct.

So if you’re cold, your hypothalamus cracks the whip on your metabolism and tells it to pump up your jam (or ham. Sandwich). You can also:

• Shiver – tiny muscles do little wiggy dances for you, which expends energy and therefore releases heat.
• Sit in the sun – Enjoy one of the three forms of heat transfer called radiation. Effort free! ..Unless finding the sun is hard.

• 

  Cuddle up with your partner – Another form called conduction (heat from touch)! Effort free but somewhat situational and culturally sensitive.

Okay, what if you’re too hot? You can slow down your metabolism, or you can:

• Sweat – promote evaporation! The change from liquid to vapor ends up in heat loss, which has a cooling effect. (If you’re in a humid area you’re screwed. Sorry New Orleans!)
• Sit in the shade! = less radiation. Effort free! Unless finding a tree is hard.

• 

  Um, convect? Convection is the third form of heat flow. It’s when the motion of a fluid (air or water) carries the heat away from the source (b/c heat rises. Think a pot of boiling water). Typically for us, air comes near us, grabs the heat and runs! Stay still and it will absorb your heat, but then just stay. Hence goosebumps that make your hair stand out and trap air so that it can’t run away with your heat. It’s also why blankets and wet suits work to keep us warm. So if you’re hot, take off your wet suit and blanket. Perv.

Jungle (and Other Biomes) Fever

But fevers are more than comfort zoning, it’s a biological weapon of sorts against bacteria that make you sick. So how does your body translate the presence of bad bacteria into heat overdrive? Here’s how it goes down:

Okay, so a bunch of bacteria sneaks in and kills off some of your cells. Vanity of vanities! But wait, twas not in vain – your dead cells have a secret weapon. Upon perishment they squirt out a bunch of death juice. This putrid concoction includes a bunch of floaties called pyrogens (‘pyro-‘ = fire, ‘-gen’ = generate. See where this is going?).

The pyrogens book it to the hypothalamus and excite cold-sensing neurons, tricking the thermostat into thinking “Jesus it’s friggin’ cold in here” and so cranks the heat. White blood cells of the immune system love heat, so they start breeding like rabbits and attacking bacteria left and right.

Meanwhile, hopefully, the temperature-sensitive bacteria and viruses stall out or die in the newfound sauna.

Extra meanwhile, you’re brain is thoroughly entertained by the Netflix binge you feel fully justified in allowing your quarantined self.

Treatment – Feed or Starve?

So, should you eat when you have a fever? “Feed a fever, starve a cold” and all that? Or was it “starve a fever, feed a cold“? Luckily, they’re both wrong, you should feed both, feed everything – feasts all around!

Now, this does of course mean healthful food. Cheetos ain’t gonna be doing you no favors. And don’t eat if you really don’t feel like it. But do force water, cuz you’re likely sweating like a piglet. (Though the hypothalamus turns a blind eye, the sweat glands are firm believers in lowering the effects of climate change).

Chicken soup is good for fever (and colds) because it’s healthy (calories + liquid), unless your grandma’s slackin’ and bought a tin of  chicken byproduct and hydrogenated corn syrup. Also, steam helps break up dry mucus (showers and tea would like a shout out as well).

Will You Die?

Yes, technically a fever could kill you. Enough heat and you start denaturing proteins, as raw foodists will happily tell you repeatedly in their ironic ‘cook’books.

In the body, this can result in possible brain cell damage, convulsions, and a little ditty called death. You can treat fever by using cold compresses, avoiding excess clothing (go nekkid!), or taking Tylenol or whatever, but remember that treating the underlying issue is more important.

Commune with your inner immunity army and get the Spanish inquisition on that infection!

Photos are in the public domain except:
tardigrade: BS8236 via photopin (license)
Citric Cycle: photo by Narayanese et al, CC BY-SA 3.0,
hand: photo by Gary Settles, CC BY-SA 3.0,
pizza: photo by Martin Pool CC BY 2.0
cowbell: Schoppernau Cow via photopin (license)
Walken: photo by John Harrison, CC BY-SA 3.0