A capillary aerosol generator is disclosed. The generator comprises a capillary passage (10) and a heat capacitor. The capillary passage (10) is adapted to form an aerosol when at least some of the liquid material in the passage is heated to volatize. The heat capacitor comprises a phase change material (40) that is in thermal contact with the capillary passage (10). The phase change material (40) changes phases at a temperature that is approximately equal to a temperature that is sufficient to volatize liquid material in the capillary passage (40).
