What is the reason for variation in body temperature?

Q: I am having a host of problems. I am a heart patient. Some time back I had fever in the range of 99-102 degree F (most of the time 99-100). The fever was accompanied by chills which continued even after my fever disappeared. I took paracetamol, cefran etc. Presently my temperature fluctuates from 95-98.6 depending on my entry and exit from air conditioned rooms and it is as if it changes with atmospheric temperature. I have no fever now but chills do not go away. I have to use blankets in a weather which till some time back I was myself finding unbearably hot (for a normal person the heat is unbearable). The peculiar thing is that after some time I can bear the A.C. and then I get chills again and then again I feel hot. All this is irregular, inconsistent and almost incomprehensible. I have gastrointestinal problems for which I am on anti spasmodics. Can this be the cause? Can Avil (recommended by a physician) help me?

A: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.