Let's approach the question this way: Why does a fever occur, and what would happen if you didn't have a fever?
Long ago, most kinds of bacteria figured out where they most like to live. Some insane critters decided that they like to live only in the hot springs (and are called thermophiles), some elected to grow in your fridge (called psychrophiles), but the vast majority prefer the nice warm, moist environment of an animal host. That's you.
When enough bacteria manage to eke out a nice living for themselves in your throat, lungs, or other body part, your body kicks into defense mode. One plan of attack involves mobilizing vast hordes of immune cells, which actually hack through many of your own cells in their attempt to get at the bad guys. Can't break an omelette without making eggs, you know.
But the body has another, complementary, elegant solution to the matter. Since the bacteria have so nicely adapted themselves to living at your body temperature (averaging 98.6 degrees Fahrenheit), the body says... "Aha! We'll burn 'em out!"
Your body turns up the heat. It stimulates muscles, makes the heart pump faster, and increases its own internal thermostat. The increased temperature makes life very difficult for the bacteria, who can easily cook in this suddenly hostile environment. The temperature increase also makes those microorganisms much more sluggish, making them easy targets for your immune system.
Then, when the forces of darkness has been vanquished, your body "breaks" the fever, and you cool down (and often have sweats as your body attempts to cool off).
So, given a choice between having a fever as a defense mechanism, or having your body overrun by bacteria? In this case, the fever is "good".
So why do we so often attempt to thwart our body's natural and effective response? We take anti-inflammatories and fever-reducing medications in order to feel better... but this only prolongs our healing process. We hope that we'll be able to forge on through our sickness, but then the sickness lasts twice as long. Because we end up fighting against our body!
Although you may want to snuggle under a blanket for at least a month, the best thing to do with a fever, believe it or not, is to go to your local Activator Methods chiropractor. The great thing about the Activator is that it's so gentle. During a fever, your whole body tends to become more sensitive, and the low-force adjusting method of the Activator is unlikely to jar your teeth from your mouth (if you know that feeling). The chiropractic adjustments are designed to help your body's nervous system work at top capacity during the fever, because the nervous system has to coordinate your immune system, your internal thermostat, and all your other regular functions as well.
So, to sum up, I personally think fevers are "great". I never take anything for a fever, because I want my body to function at top capacity so I can be back to normal as soon as possible. When you say, "I feel so sick", what you really mean is "I feel healthy, because my body's doing exactly what it should in order to protect me from bacteria and keep me strong, although my limbs are surprisingly weak and I'm going to lay down now."
If you weren't healthy, you wouldn't have the fever, because the fever is your body's expression of natural, healthy living. Your fever keeps you alive: if you didn't cook the bacteria, you'd wouldn't be long for this world.
Caveat: although rare, if your fever rises above 104 degrees Fahrenheit, you'll need immediate medical intervention. In this instance, your body has actually lost the capability to control its own internal temperature, and is in danger of having the temperature rise out of control. Also, for the record, meningitis is bad. I'm just talking about run-of-the-mill winter fevers here.
UPDATE: There is an interesting article on children's fevers published yesterday in the New York Times that dovetails nicely with my blog post. It was written by a pediatrician, and discusses the prevalance of fear and worry about fever.