An IR camera (FLIR ThermaCAM S65 HS FLIR Systems, FLIR Systems AB, Boston, MA) will be positioned directly above the exposed anterior thorax and abdomen. This camera can produce sequences of high-definition digital IR images with an accuracy of 0.1º C. Thermal emissivity is set to 0.98 and the accuracy of the camera will be regularly checked against a black body with a traceable temperature source (Model IR-2103/301, Infrared Systems Development Corp., Florida, USA). IR images are taken at regular intervals to register the rate and pattern of skin recovery for 3 minutes after a mild cold challenge. Images are electronically stored and afterwards processed using image analysis software ThermaCAM Researcher Pro 2.8 SR-1 (FLIR Systems AB).