Homeostasis and negative feedback do not mean that body temperature is always constant. For
example, when you have an infection, your body temperature may increase and you may
develop a fever. The fever helps your immune system fight the infection. This flowchart shows
how a person who has an infection develops a fever.
Body
temperature
is 37°C.
Cells that are fighting an infection release a chemical
signal that is carried by the blood to the temperature
control center. This chemical signal increases the set
point for temperature regulation to -39°C (102°F).
Temperature control center detects that body
temperature is below the new set point.
Shivering
More heat generated,
so body warms.
Body temperature increases
to the higher set point.
7. Notice that the person described in this flowchart is shivering, even though his body
temperature is at the normal set point = 37°C. Explain why he is shivering.