Pyrexia

Py·rex·i·a
Noun,
Medical term denoting fevers.
Medical Dictionary

Yes, I named my blog after Pyrexia, the medical term for 'fever'.
I only swapped the 'y' for 'u' because in Ancient Greek, we the sign for 'y' was a 'u'. Not to mention there's already another blog with the name 'Pyrexia'.
.. Alright. This is the second time in a month I'm coming down with a bloody darn fever. Funny thing? Yesterday was my birthday. I was ill on my birthday.
Illnesses strike whenever they want, wherever they want.

I didn't measure my body temperature, but I'm guessing its close to 39 °C.
Sometime ago, my body temperature used to linger around 38 °C without me being ill or feeling like crap. I'm weird like that.
By now, my regular body temperature is about 37.5 °C, which is still a bit higher than the average of 37 °C, but it falls within the range of normal again.
I never knew an elevation of 1.5 °C could make me feel this crappy, but I guess I underestimated the power of a good old fever bout.

So when do we call it a fever?
According to the book 'Fundamentals of Anatomy and Physiology' by Bartholomew, 'fever is an elevation of body temperature that accelerates tissue metabolism and the activity of defenses'. The book also states that a body temperature above 37.2°C (99°F) could be considered feverish. In this sense, even my regular body temperature of 37.5°C could be considered feverish, even when I feel perfectly fine.
The accepted temperatures are different for every measuring spot. For the armpit and ear canal, anything above 37.2°C is to be considered feverish.
For the mouth, this is 37.7°C and for the rectum it is 37.5~38.3°C (Don't blame me on this crappy data, I pulled it off wikipedia)
Throughout the day, your body temperature fluctuates by about 0.5°C

Fever occurs whenever the temperature-regulating center(the hypothalamus) sets your desired body temperature above normal values, after which your body uses various mechanisms to generate heat.

Several things could cause your hypothalamus to raise your desired body temperature:
*Inflammation
*Infection
*Tissue damage
*Immunological diseases
*Metabolic disorders

I might have missed some. Also, your fever might be so mysterious that doctors just give up about looking for the cause.

As long as your body temperature doesn't cross the limit of 40-41°C, a fever might be beneficial. Some viruses and bacteria thrive at certain temperatures, and a higher body temperature can knock them off balance.
Aside from that, it boosts your metabolism by 10% per 1°C rise.
Above 42°C, your high body temperature will damage your own body, which might result in death, so please, do call a doc when you reach 40°C.

Ranges for certain states:
Hypothermia: <35°C (This might be a serious condition. A body temperature below 30°C might kill you. But by then you'll be as incoherent as a drunk on weed.)
Normal: 36.5~37.5°C. 36°C
Fever: >37.5°C
Hyperthermia: >37.5°C (Potentially dangerous)
Hyperpyrexia: >40.0°C (Ready the coffins!)

So what's the difference between Fever and Hyperthermia?
The mechanisms behind it.
For fever, your body consciously sets the set point above 37.5°C. For hyperthermia, your body temperature set point is still within normal ranges, but your body temperature rises above this set point anyway. Reasons for this could be drug use, exercise and heatstroke.

Hope this info will save you a potential trip to the hospital or a single trip to the graveyard for many years to come.

Ainyria