The invention relates to a radiation emitting device (1) for application near mammal tissue (2), comprising: a substrate (3) having a front surface (4) and an opposing back surface (5), said substrate accommodating at least one radiation source (6) on said front surface (4). Said at least one radiation source (6) is arranged for applying energy on said mammal tissue (2). A heat spreading section (7) is arranged on said back surface (5) of said substrate (3) in thermal contact with said at least one radiation source (6). Said heat spreading section (7) has an extended area (8) extending beyond said substrate (3) in a direction substantially parallel to said substrate (3). Said extended area (8) of said heat spreading section (7) is arranged in thermal contact with said mammal tissue (2).