Fig. 7. Calculated CBFs for 130 brain minus carotid temperature gradients (T_brain–T_carotid). The gradients were calculated by obtaining a mean T_carotid for 0.1°C intervals of T_carotid and subtracting that mean value from the corresponding average T_brain. (A) CBFs above the upper maximum CBF (pink line) cannot be achieved and the gradients associated with these CBFs are produced by SBC. (C) CBFs below the minimum CBF (yellow line) are unable to provide adequate oxygen and glucose to the brain (see text) and the gradients measured cannot be the result of reduced CBF. They must result from a brain warming mechanism. (B) Gradients between A and C can be produced by changes in CBF alone but are likely to be the result of changes in both CBF and SBC.