I'm starting to shiver. Maybe I need to sit down.
Shivering is an example of my body reacting to a stimulus of cold weather and trying to maintain a constant temperature or homeostasis.
Temperature sensitive skin cells act as receptors that signal to the control center in the brain
In this case, my body is trying to get my temperature back to a set point. So by shivering, my skeletal muscles contracting act as effectors that warm my body temperature