- coldness
The parvovirus attacks the entire organism. When the brain detects an attack, it activates the body’s primary line of defense, the immune system. The immune system then heats the body in an attempt to recalibrate itself while destroying the parvovirus invader. The elevated body temperature produces fever, which is accompanied by chills. Typically, fevers are effective against the majority of bacterial and viral infections. The hypothalamus regulates temperature.
When this region of the brain initiates the production of pyrogen proteins, these molecules then attach themselves to the nerves in the lower back. This is what causes the body temperature to increase. The greater the concentration of these pyrogens in the blood, the higher the fever and the greater the shivers. During a fever, the body experiences a “chill” between its initial temperature and the new temperature it is attempting to achieve. Chills are transient.
