Thermoregulatory control of skin temperature involves both central reflexes facilitated by sympathetic vasoconstrictors and vasodilator nerves, along with a variety of local thermal control interactions mediated by several vasoactive pathways. These reflexes interact with both the nutritional capillaries and intrinsic arteriovenous shunts to change the vascular flow. Transradial cardiac catheterization almost universally results in endothelial damage from access sheath trauma and may, therefore, damage the thermoregulatory control to the hand as an unintended consequence of the transradial approach. This question of whether transradial catheterization may be associated with changes in hand blood flow was explored in a paper by Maki et al, in this issue, using serial hand thermography.