Your skin acts as you body’s own thermostat, meaning that it serves an important purpose in helping to regulate your core temperature. Because you can become seriously unwell if your internal temperature dips below or rises above the accepted ‘safe’ zone of roughly 37°C, your skin is working constantly to ensure this doesn’t happen. Sweat helps to keep the body cool when temperatures rise, and in cold situations, blood vessels close to the surface of the skin tighten in order to retain heat.