A guide wire is described for navigating body channels such as vessels. The guide wire can include an elongated member having a proximal portion and a distal portion, and a fluid passage to transport a fluid from the proximal portion to the distal portion. The distal portion of the elongated member can include a shape memory material with two way memory effect. The shape memory material can have a transition temperature less than a body temperature such that the distal portion has a first shape at the body temperature and a second shape different from the first shape at a temperature less than the transition temperature.
