Congenital insensitivity to pain with anhidrosis (CIPA) is a rare hereditary recessive disease of the nervous system that causes affected individuals from feeling pain or temperature, and prevents them from sweating appropriately in response to an adequate stimulus. Since, Marcellus is diagnosed with such disease, he is also unable to sweat.
Marcellus has been diagnosed since childhood with a condition called CIPA, which stands for congenital insensitivity to pain with anhidrosis. This means that, in addition to being unable to feel pain, Marcellus is also unable to sweat
