Figure 3.
Redrawn (freely) from the classical paper by Barcroft and Edholm to illustrate the effect of local temperature on limb blood flow, recorded by venous occlusion plethysmography. The numbers on the right are the temperatures of water in the plethysmograph in which the subject's arm was enclosed at time zero. At temperatures above 35C, flow increased steadily, the higher the temperature the higher the peak flow reached.