The aerosol-generating article includes a retention medium defining a lumen, a side surface of a first end of the retention medium defining an opening of the lumen, and at least one frangible capsule selectively insertable into the lumen through the opening, the at least one frangible capsule releasably containing a substrate, the retention medium being configured to absorb and retain the substrate after a release of the substrate once the at least one frangible capsule is ruptured by an external force, the retention medium being devoid of the substrate prior to the release of the substrate from the at least one frangible capsule.

A peritoneal dialysis (PD) system includes a PD fluid pump, a PD fluid heater positioned and arranged to heat fresh PD fluid pumped by the PD fluid pump, and a phase change material (PCM) device positioned and arranged to receive fresh PD fluid heated by the PD fluid heater. The PCM device includes a PCM having a melting temperature selected so that the PCM melts when overheated fresh PD fluid contacts the PCM, removing heat from the overheated fresh PD fluid.