A, The observed mean T1 relaxation time in frontal white matter (squares), cortical gray matter (triangles), and ventricular CSF (dots) as a function of the core body temperature of all subjects. Added are the estimated slopes of T1 change per temperature. B, The observed mean T2 relaxation time in frontal WM (squares), cortical GM (triangles), and ventricular CSF (dots) as a function of core body temperature of all subjects.