An aerosol-generating system is provided, including a nicotine source; a volatile delivery enhancing compound source downstream of the nicotine source and including an acid; heating means for heating the nicotine source; and a physically separate heat transfer barrier between the nicotine source and the volatile delivery enhancing compound source. The heating means is configured to heat the nicotine source to a temperature of between about 80° C. and about 150° C. The heat transfer barrier is configured so that the temperature of the volatile delivery enhancing compound source is less than about 50° C. when the nicotine source is heated to a temperature of between about 80° C. and about 150° C. by the heating means.