Mobile devices currently have a positive role to play in health care system. People have mostly used apps to record their daily physical and health conditions such as weight, steps, calories, meals, heart rate, sleep time, etc. This paper presents face color analysis by body temperature for a mobile device application. First, we extract a skin image patch from a face picture taken with a mobile camera. The skin image patch can extract from the bottom of left eye and the right side of nose using the face part recognition method. The skin color is transformed to CIELAB color space from RGB and we analyzed the change of skin color divided into color channels, a* and b* according to temperature. The experiment results showed that the change of a* color channel is related in high temperature. The proposed method can provide many benefits for mobile health care system effectively by integrating with existing apps.