A. Schematic illustration of experimental setup. B–F. Images of ultraweak photon emission from human body. B. Image of the subject under light illumination. C. Image at 10:10. D. Image at 13:10. E. Image at 16:10. F. Image at 19:10. G. Image at 22:10 with a calibration bar which indicates the estimated radiation intensity expressed by photon number per unit of time per unit of skin surface. H. Daily rhythm of photon emission from face and body from 5 volunteers. Significant difference from the photon emission at 10:00 AM (n=15, Mean±SD; **P<0.01, *P<0.05). I. A typical thermographic image of the subject from Fig. 1B–G.