Three thermograms of an obese woman, showing her in frontal (left) profile and rear aspect. Thermography maps the distribution of heat over the body surface, giving a colour-coded image ranging from white (hottest) through red, yellow, orange, green & blue to black (coldest). Obesity is a condition in which excess fat has accumulated in the body, mostly in the subcutaneous tissues. The simple cause is over- indulgence in food - eating more than is required for daily metabolic activities. Obesity is one of the most common nutritional disorders of recent years.