Subjects will undergo Existing Procedure EP- Passive Thermography PT for Phase I and Existing Procedure EP- Active Thermography ATLIC/ATPC for Phase II, with Duplex Ultrasound being the existing procedure that is considered as more reliable in clinical practice. Existing Passive Thermography will be used to setup the baseline data for Phase I. The currently under-development temperature mapping method (Active Thermography) that involves application of cooling (either pulsed or lock-in cooling) over the skin will be utilized for Phase II.