Final answer:
The temperature of the water is registered in the parietal lobes of the brain, which are responsible for processing sensory stimuli including temperature, touch, and taste.
Step-by-step explanation:
When you place your hand under the faucet to feel and adjust the temperature of the water, the temperature is registered in the parietal lobes of your brain. These lobes are responsible for processing sensations, including temperature, touch, and taste. The parietal lobes, situated behind the frontal lobes at the top of the head, play a crucial role in the interpretation of sensory information and are integral to spatial orientation and navigation.