Fever Feedback Loops

Fever

An elevated body temperature above the normal range (around 37°C) usually in response to infection, inflammation, or other illness.

Pyrogens

Substances, often produced by bacteria or the immune system, that trigger the hypothalamus to raise the body’s set point temperature.

Hypothalamus (in fever)

Brain region that acts as the control center; raises the body’s temperature set point in response to pyrogens.

Negative Feedback Loop (in fever)

A mechanism that attempts to restore homeostasis after the body temperature rises, though initially the set point is increased to fight infection.

Effectors (in fever)

Mechanisms such as shivering, vasoconstriction, and increased metabolism that generate heat to reach the new set point.

Fever Resolution

When pyrogens are removed, the hypothalamus lowers the set point back to normal, triggering sweating and vasodilation to cool the body.

Interaction with Immune System

Fever enhances immune function by increasing white blood cell activity and inhibiting pathogen growth.