Fig. 5. (A) Minimum and maximum (blue) and mean (red) T_jugular and (B) minimum and maximum (light blue) and mean (dark blue) T_brain plotted against T_carotid. At T_carotid below 38°C brain temperature stays constant; between 38°C and 39.5°C brain and carotid temperatures approach each other as CBF increases and SBC begins. Above 39.5°C typical SBC is evident. At carotid temperatures below 37°C all three jugular temperatures are above carotid temperature, but at higher carotid temperatures mean and minimum jugular temperatures become cooler reflecting an increase in REHL. Values are means ± s.d. but note that error bars disappear from the mean jugular trace at low T_carotid because data from only two animals could be matched to corresponding data points for T_carotid.