The sensation of cold from exposure to a cold environment, or an episode of shivering with paleness and a feeling of coldness. Chills may occur at the beginning of an infection and are usually associated with a fever . Chills are caused by rapid muscular contraction and relaxation and are the body's way of generating heat when it perceives that it is cold. Chills often herald the onset of a fever or increase in the degree of fever. Chills may also represent a very significant and consistent finding in certain diseases such as the chills seen in malaria .
Children tend, in general, to develop higher fevers than adults.
Even minor illness may produce high fevers in younger children. Infants tend not to develop obvious chills but any fever in an infant of 6 months or less should be reported to a health care provider. Fevers in infants 6 months to 1 year should be reported unless the parent is absolutely sure of its cause. There may be other causes of chills. This list is not all inclusive, and the causes are not presented in order of likelihood.