A dermatological medical device (1, 15, 20, 53, 56, 65, 67, 68, 72, 77), comprising: a distal end for positioning at a region proximal a target therapeutic region of tissue; an output port at the distal end; an energy source (8, 19, 402) configured to generate optical energy to be output from the output port to the target therapeutic region of tissue; and a control device configured to control delivery of the optical energy at an initial power density of 1 to 400 W/cm 2 during a first optical treatment time period required to increase the temperature of the target therapeutic region of tissue by at least 2°C and no more than 8°C for heating the target therapeutic region of tissue to reach a therapeutic temperature range so as to induce an expression of heat shock proteins at the target therapeutic region of tissue, followed by a delivery of the optical energy having a second optical treatment time period during which the optical power density is reduced with respect to the initial power density or the amplitude and/or pulse configuration of the optical energy is modulated in order to maintain the temperature of the target therapeutic region in the therapeutic temperature range so as to achieve thermal exposure of the target region of tissue to the therapeutic temperature range for a thermal exposure duration of 2 to 10 seconds. a distal end for positioning at a region proximal a target therapeutic region of tissue; an output port at the distal end; an energy source (8, 19, 402) configured to generate optical energy to be output from the output port to the target therapeutic region of tissue; and a control device configured to control delivery of the optical energy at an initial power density of 1 to 400 W/cm 2 during a first optical treatment time period required to increase the temperature of the target therapeutic region of tissue by at least 2°C and no more than 8°C for heating the target therapeutic region of tissue to reach a therapeutic temperature range so as to induce an expression of heat shock proteins at the target therapeutic region of tissue, followed by a delivery of the optical energy having a second optical treatment time period during which the optical power density is reduced with respect to the initial power density or the amplitude and/or pulse configuration of the optical energy is modulated in order to maintain the temperature of the target therapeutic region in the therapeutic temperature range so as to achieve thermal exposure of the target region of tissue to the therapeutic temperature range for a thermal exposure duration of 2 to 10 seconds. an energy source (8, 19, 402) configured to generate optical energy to be output from the output port to the target therapeutic region of tissue; and a control device configured to control delivery of the optical energy at an initial power density of 1 to 400 W/cm 2 during a first optical treatment time period required to increase the temperature of the target therapeutic region of tissue by at least 2°C and no more than 8°C for heating the target therapeutic region of tissue to reach a therapeutic temperature range so as to induce an expression of heat shock proteins at the target therapeutic region of tissue, followed by a delivery of the optical energy having a second optical treatment time period during which the optical power density is reduced with respect to the initial power density or the amplitude and/or pulse configuration of the optical energy is modulated in order to maintain the temperature of the target therapeutic region in the therapeutic temperature range so as to achieve thermal exposure of the target region of tissue to the therapeutic temperature range for a thermal exposure duration of 2 to 10 seconds.