The aim of this study was to evaluate the temporal artery thermometer by comparing temporal artery and axillary thermometer temperature measurements with rectal thermometer temperature measurements in neonatal patients. The investigators measured temporal artery, axillary, and rectal temperatures of 49 infants. Temporal artery temperature was measured using an infrared temporal artery thermometer, and the results with this device were compared with axillary temperature (clinical standard) and rectal temperature (gold standard). The difference between rectal and temporal artery temperatures was compared with the difference between rectal and axillary temperatures for each infant, and the data were analyzed based on weight, postmenstrual age and bed type - open crib or incubator.