An apparatus for delivering energy, and in particular laser energy, to a tissue is adapted to minimize or eliminate burn back caused by contact between the energy delivery apparatus and bodily fluids by (i) preventing the energy delivery apparatus from contacting bodily fluids or tissues that might burn or cause the apparatus to burn； and/or (ii) monitoring the apparatus to detect overheating in order to withdraw the apparatus or control the energy supply in case overheating is detected. The apparatus is applicable, by way of example, to treatment of blood vessels using endovascular techniques.
