Answer
Stabilizing mechanisms are called negative feedback because they reverse or negate the change.
Work Step by Step
Negative feedback reverses changes while positive feedback promotes changes. Let's look at an example:
The body's set point temperature is 37$^{\circ}$C. If the person is in a very hot room, their body temperature might rise to 37.5$^{\circ}$C. Homeostasis kicks in and activates cooling mechanisms to reverse the rise in temperature. We are negating and reversing the rise in temperature, which we call negative feedback.
Likewise, if the person is placed in a very cold room and their body temperature drops below their set point, homeostasis also kicks in to reverse the fall in temperature and promote actions to warm up the body. This is also negative feedback.
