In his groundbreaking book, “Phantoms In The Brain”, charasmatic neurologist V. S. Ramachandran demonstrates how the brain “remaps” the missing limb to sensory areas that are adjacent on the sensory cortex in the parietal lobe. For example, with one patient he describes how the phantom hand is remapped onto the corresponding cheek. Curiously, sensations felt in the cheek are also felt in the phantom hand.
These remapped sensations are “sensory-specific” meaning that a drop of water on the cheek is felt like a drop of water on the hand, hot and cold also felt the same way. The remapping is precise enough that areas of sensation in specific areas of the phantom hand can be drawn on the corresponding cheek.