Thermographic imaging of facial skin--gender differences and temperature changes over time in healthy subjects

To assess changes in facial skin temperature over time, to identify sources of variation related to skin temperature and to evaluate interobserver reproducibility in measurements of the thermograms. 62 volunteers (32 females, 30 males, mean age 23.4, range 19.5-29.5 years) underwent thermography of the face (left and right side lateral images) on four occasions with approximately 2 months between each session. Three observers recorded the images and marked regions of interest (ROIs) in each image using dedicated software. Smoking, exercise habits and use of oral contraceptives were recorded. A significant difference between sessions (≤1 °C, p