Nowadays, medical and technological breakthroughs allow the survival of infants born between 28 weeks and 33 weeks of gestational age (GA). However, many of the procedures that are a necessary part of postnatal care can be, by nature, painful and stressful. Consequently, medical staff are faced with the necessity to evaluate pain and discomfort in preterm infants. Pain and discomfort is most frequently assessed through multidimensional scales (PIPP ' DAN) which are based on the observation of both physiological (heart rate; respiratory rate) and behavioral reactions (facial and body movements). Unfortunately, due to the physiological immaturity of preterm infant of low gestational age (< 28 weeks of GA), these scales raise various difficulties. The present multidisciplinary project gathers around the neonatal intensive care unit of Clemenceau Hospital, Caen, France, researchers from a laboratory of Psychology (PALM JE 2528) and a laboratory of Computer Sciences (GREYC, UMR CNRS 6072) of the university of Caen Basse-Normandie, and electronic engineering support of an industrial partner (GREY-SOFT) to bring an innovative technological solution to the difficult problem of pain and discomfort evaluation in infant born between 28 and 33 weeks of gestation. The project is aimed at evaluating painful and discomfort in preterm infant from infrared thermographic measure. The main goal is to identify specific signatures of the thermal variations of the whole body of the baby confronted to painfull and stressfull situations.