Infrared imaging used to observe the thermal response of the human skin to local cooling

Abstract Thermal imaging can provide novel data in laboratory exercises in physics and especially in quantitative physiology, for both quantitative analysis and modelling. In this paper we describe an exercise where the skin of the forearm is briefly cooled locally, the skin’s temperature recovery is observed with a thermal camera and the observations are analysed with the aid of simple thermal models. Although the thermal models applied are simple, they introduce several concepts from heat transfer and inspire quantitative modelling of the experimental data. The former model is very simple and is based on Newton’s law of cooling and it invites a second slightly more involved model including some analysis of heat transfer. The observed rate of temperature recovery is shown to be related to thermal properties of the skin and perfusion, and the experiment is a non-invasive measure of one aspect of the human thermoregulation. Thermal cameras are handy, they are becoming ever more accessible and can reveal novel insights when observing various physiological thermal process. This experiment may be of particular interest to students in health and biosciences that are taking undergraduate general physics courses and training data analysis.