Disclosed herein are medical systems involving the novel use of lasers in a way to transfer a desired amount of energy to deeper tissues, such as deep dermis, fat, deep vessels, fascia, tumors and others, without burning the skin, in particular the skin surface. A medical system (10) comprises a laser beam delivery system (21) producing a plurality of laser beams (1a-1d) for simultaneously or alternately irradiating the deep tissue target structure (5) from multiple directions via the skin surface (2), wherein the laser beams (1a-1d) individually are individually adjusted to have an energy level insufficient to ablate and/or burn the skin (2). The target structure (5) comprises a deep tissue target structure (5). The laser beams (1a-1d) have a combined energy level at their point of intersection to achieve a preselected thermal gradient sufficient to treat the deep tissue target structure (5). The medical system (10) further comprises a cooling device for cooling the skin surface (2) during irradiation. A corresponding method and use is also disclosed.