An aerosol delivery system has a fluid-transfer article with a first region for holding an aerosol precursor and a second region to which the aerosol precursor is transferred from the first region. The second region includes an activation surface which interacts thermally with a heater of the aerosol delivery system to form an aerosol from said aerosol precursor. The fluid-transfer article includes at least one heat activatable valve which controls transfer of aerosol precursor from the first region. The or each valve may be between the first and second regions, or may form the second region so that a surface of the valve or valves forms the activation surface. The or each valve may limit or prevent escape of aerosol precursor from the fluid-transfer article, when the heater is not active, but allow the aerosol precursor to reach the activation surface when the aerosol delivery system is in use.
