A cooling head (1) for a skin treatment laser has a body (2) with a mount (3) at one end for attachment to a laser head (12). A cooling surface (4) at the other end is used for application to a patient's skin, and a coolant chamber (5) is disposed between the mount and the cooling surface. The chamber has wall portions (60, 61) transparent to non-visible laser light to allow a laser beam to be passed from the mount to the patient's skin through the cooling surface. A coolant inlet (9) and outlet (8) provided in the body enable the supply and removal of coolant in order to cool the cooling surface and an extraction port (42) enables removal of debris from the treatment area and is connected to a vacuum source. A window (100) is provided in the body optically transparent in the visible light range to allow the laser beam at the cooling surface to be viewed.
