Thermocouples provide information about ski and skier performances and snow conditions. VI skating superimposed a strong, cyclic signal on the general heating due to friction. The power spectra of these cycles gave information about the skier's technique. The greatest temperature response at the base of a skating ski was just behind the foot, where the ski is heavily loaded. The longitudinal profiles showed generally increasing temperatures along the length of the ski. Harder, more durable waxes are needed behind the foot, where most of the weight is carried, but the gliding temperatures are highest there. Heating increased with both speed and solar input. Solar radiation absorption heats the ski base directly and raises its temperature considerably. The color of the ski base and the amount of sunshine should be considered when choosing a wax.