The maintenance of a stable temperature is of the utmost importance for the proper functioning of the brain. Brain temperature is tightly linked to mitochondrial energetics. Although Parkinson's disease is characterized by mitochondrial dysfunction, no data are available on brain temperature. We measured the temperature in the visual cortex and in the centrum semiovale at rest by proton magnetic resonance spectroscopy in patients with Parkinson's disease and in age-matched and sex-matched control participants. We report evidence of increased temperature in the visual cortex and, to a minor extent, in the centrum semiovale of patients with Parkinson's disease. The increase in brain temperature is best explained by an energy loss along the oxidative phosphorylation/respiratory chain.