Body Temperature, Fever Mechanism, and Immunity

Body Temperature, Fever Mechanism, and Immunity

It is commonly believed that human body temperature is regulated near
98.6 degrees Fahrenheit. How does this regulation work? What are the
temperature sensors? What reference (i.e. temperature standard) is
used within the body to regulate the temperature within a narrow
range? What triggers the body?s control logic mechanisms to raise or
lower the body temperature? What mechanisms are used to increase and
decrease the temperature? Is it unusual to have a ?normal? body
temperature remain significantly below 98.6? Are there known
syndromes, circumstances, or medical conditions related to chronically
low body temperature, or other irregularities in regulating body
temperature?

Related to this, what sensors, control logic, and temperature control
mechanisms comprise the fever mechanism?

Finally, what effect does higher or lower body temperature have on the
human immune response? We know that viruses cannot thrive at
temperatures much above those caused by a fever. Does the increased
body temperature associated with a fever improve the immune response
by weakening viruses, or by speeding chemical reactions? Does
(artificially) reducing a fever prolong an infection? What conditions
could lead to a person suffering from an infection but not running a
fever?

An acceptable answer will address many of these questions, and cite
authoritative references to substantiate the information provided.