or '''chills''' is
Shaking occurring during a high
Fever . It occurs because
Cytokines and
Prostaglandin s released as part of an
Immune Response increase the set point for body temperature in the
Hypothalamus .
The increased set point causes the body temperature to rise (
Pyrexia ), but also makes the patient feel cold until the new set point has been reached. Rigors occur because the patient is effectively shivering in a physiological attempt to increase body temperature to the new set point.
