Relationship between %FMD and % resting vascular tone. FMD is increase above baseline following cuff release, and tone represents resting diameter in relation to maximum diameter. Data points represent values from room temperature as well as heated conditions for six subjects on day 1 and for four subjects on day 2 (20 total). R2 value of .73 demonstrates the positive relationship between FMD and tone. As tone increases, resting diameter will decrease thus allowing for a greater FMD.