You are getting very sleepy. You can barely keep your eyes open. Your eyelids are so heavy they feel like lead weights. Before you know it, your face gently falls onto your Physiology book and you are fast asleep. As you sleep, the heater in your room turns on and the temperature starts to rise. The change in your core temperature is detected by that send signals to a(n) which decides whether to make a change to maintain . In this case it decides to lower your temperature and sends a signal to that increase sweating. This action successfully lowers your temperature back to normal and demonstrates the process of .