[noun] ー
an acutely disturbed state of mind results in confusion and disorientation.

I suffer from fever quite a lot, mostly due to exhaustion, acute upper respiratory infection, or even simply mental stress. Like today, for example. I pushed myself too far in running yesterday and I went to bed as late as 2:20 in the morning.

When we have a fever, our body feels weak, lethargic, sluggish. Our breathing gets deeper and more rapid, that’s because our body tries to release heat. We get so thirsty because the evaporation gets more intense which results in dehydration. Not to mention, the muscles and joints pain. But for me personally, the most significant change when I have a fever is the cloudy mind. I can’t describe the feeling perfectly, but in general it feels like I’m trapped in the middle of this white suspension of an in-between gas and fluid. It’s not exactly called a state of delirium, but it definitely causes mental confusion. Unfortunately, it’s not the worst thing that can happen in fever.

The most unpleasant thing would be the vivid dreams. It’s not that kind of blissful dream. In contrary, the vivid dreams that appear in our feverish sleeps are nightmares. The nightmares vary from time to time and differ from one person to the others. I have two most frequent nightmare scenarios: 1) I am stuck or trapped in this endless net/web of black sticky strings with endlessly white dimension as a background. What frightens me is that the more I struggle, the more I feel suffocated. And 2) There is some kind of deranged and huge black creature that chases me through, again, an endlessly white dimension. The creature is actually more of an entity made of pitch black shadow trying to engulf me in it rather than a solid thing. The problem with dealing with vivid dreams is, of course, now matter how aware we are of the dreams, you can not just decide to get out of it. Is it not frightening to be trapped in your dreamscapes? Feeling like inception, isn’t it?

What does actually cause these terrible nightmares when we have fever? This explanation will be quite medical. Fever is caused by substance called Pyrogens. Pyrogens can be originated from outside our body (exogenous, e.g. from bacteria) or produced by our own body (endogenous, e.g. interleukins). These pyrogens mess up our central body temperature controller up there inside our brain, making our body thinks that the temperature around us is way much colder then it actually is. Beside messing up the temperature controller, the pyrogens also make our brain lose control of the limbic system. This part of brain controls human emotion. When we sleep, dream occurs in the very first stage of sleep called Rapid Eye Movement (REM) stage. In this stage, normally the limbic system generates previously (yet subconsciously) determined dreams. But during fever, the brain loses control the limbic system and causes it to fall into a hyperactivity state which makes it no longer be able to control dreams smoothly like it’s supposed to. Therefore, vivid and scary dreams occur.