Variations in the body's temperature and even a sense of chillinesss may result from a poorly defined and non-specific dysfunction of the temperature regulating center in the brain, the hypothalamus. Sometimes there is a fault in the autonomic nervous system such as dysautonomia.
While there is no curative treatment, a course of daily vigorous exercise will help. Some patients benefit from anti-anxiety medications, while others respond to antihistamines. Demerol or ethidine has been used in severe cases, but this is not of general application.
A physician may need to rule out serious disease such as AIDS (HIV), tuberculosis, brucellosis, lymphoma, or endocarditis, but there is usually clear evidence of such causes.