“Why do I have a fever?
Oh, is it because the white things are attacking the green things?
And when I take medicine it helps the white things do their job so then the fever goes away.
I used to think that I had a fever because there was a feather in my brain.”
Laughing, Laughing, Laughing Max over that one.
“Uhhhh, yes. It is. Actually. (not the feather part!)
The White Blood Cells are fighting the infection in your body.
You learned that from Magic Schoolbus, I suppose?”
A fever occurs when the thermostat resets at a higher temperature, primarily in response to an infection. To reach the higher temperature, the body moves blood to the warmer interior, increases the metabolic rate, and induces shivering. The chills that often accompany a fever are caused by the movement of blood to the body’s core, leaving the surface and extremities cold. Once the higher temperature is achieved, the shivering and chills stop. When the infection has been overcome or drugs such as aspirin or acetaminophen have been taken, the thermostat resets to normal and the body’s cooling mechanisms switch on: the blood moves to the surface and sweating occurs.
When an infection occurs, fever-inducing agents called pyrogens are released, either by the body’s immune system or by the invading cells themselves that trigger the resetting of the thermostat.
Fever is an important component of the immune response, though its role is not completely understood. Physicians believe that an elevated body temperature has several effects. The immune system chemicals that react with the fever-inducing agent and trigger the resetting of the thermostat also increase the production of cells that fight off the invading bacteria or viruses. Higher temperatures also inhibit the growth of some bacteria, while at the same time speeding up the chemical reactions that help the body’s cells repair themselves. In addition, the increased heart rate that may accompany the changes in blood circulation also speeds the arrival of white blood cells to the sites of infection.