IR color thermography was used to visualize skin temperatures in 2 athletes standing and running in an outdoor environment at 20.degree. C and in a climatic chamber at 11.degree. C. Temperature distributions and changes were recorded on film and analyzed. Mean skin temperatures determined by this method were compared with skin temperatures obtained with a probe thermocouple. During running, skin temperatures were higher over muscles than over other structures and the distribution differed dramatically from that observed before exercise. Regional mean skin temperatures obtained by thermography differed by up to 4.degree. C from those obtained with the thermocouple probe. Overall mean skin temperatures obtained by both methods agreed to within 1.5.degree. C.