A system and method for treating skin. The System comprises one or more ultrasound transducers and one or more pairs of RF electrodes. The ultrasound transducers are adapted to focus ultrasound energy at one or more focal volumes in the skin. The RF electrodes are adapted to deliver RF energy to the one or more focal volumes. The method comprises heating the skin to a first temperature at one or more focal volumes in the skin by focusing ultrasound energy at the one or more focal volumes. The focal regions are then heated to a second temperature, the second temperature being higher than the first temperature, by generating an RF current in a region of the skin containing the focal regions.