Obesity is linked to inflammatory diseases but effects of a metabolically active phenotype on the immune system and autoimmunity remain elusive. This work shows that the metabolic stimulus cold exposure reduces monocytes in the bone marrow and changes their phenotype in the circulation. Cold decreases neuroinflammation in the mouse model experimental autoimmune encephalomyelitis (EAE) and reduces pathogenic T cell cytokines and monocytes MHCII. Monocyte depletion abolished T cell cytokines at EAE onset, implying that cold affects T cell priming via monocyte modulation. This study provides systematic overview on the immune changes during cold and could have implications in treatment of autoimmunity.