Fig. 2From: Venous dilation effect of hot towel (moist and dry heat) versus hot pack for peripheral intravenous catheterization: a quasi-experimental studyMeasuring the venous diameter and the venous depth. The venous diameter (mm) was calculated as the average of the shortest diameter (from the upper end to the lower end of the vein) and the longest diameter (perpendicular to the shortest diameter) (= [shortest diameter + longest diameter] / 2). Venous depth (mm) was measured as the vertical distance between the skin surface and the upper end of the veinBack to article page