Atrial fibrillation is a heart condition commonly treated by cardiac ablation procedures. Since the esophagus is positioned in close proximity to the heart, esophageal thermal damage can occur during ablation. In this study, we investigate the temperature rise on the inner esophagus surface using a 2D temperature sensor array. An experimental study was performed to measure temperature by the sensor array placed on inner porcine esophagus tissue as a constant temperature heat source is applied to the inner porcine atrial tissue. A numerical model was developed to complement the experimental study.