Systems and methods are provided for detecting overexposure of skin to ultraviolet light. A system may include a thermal imaging module that captures thermal images of a person's skin. Using the thermal images, the system may determine whether the person's skin has been or is being overexposed to ultraviolet light. The system may be a fixed camera system for monitoring an outdoor area, may be a mobile device having a thermal imaging module within or coupled to the mobile device, or may be part of a tanning system having an ultraviolet light source and a thermal imaging module. The overexposure may be detected in a thermal image based on a temperature of the person's skin, a change in the temperature of the person's skin over time or a temperature difference between portions of the person's skin.