A321
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Physiological - Other
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Inflight Event / Encounter Weather / Turbulence
General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
We got to the plane and had found out the ramp was closed due to storms in the area. The plane was hot so we started the APU to cool it off. Boarding had already started. We right away started to smell dirty sock smell. We went to the aircraft odor in the QRH. It had us turn bleed and packs off. Plane was getting hot. Called MX and they had us Aircraft Smoke Odor Fumes report. We asked to deplane. Once the pax were off; we assess the crew. Pilots were fine. All flight attendants had some symptoms reported in that form. Paramedics were called and recommended they get assessed at the hospital.
On predeparture at gate in ZZZ with passengers boarding flight attendants called flight crew complaining of dirty sock smell from APU.  We ran the QRH Aircraft Odor/ Toxic Substance/ Volatile Liquid checklist on page XX-XY. We then deplaned the passengers.   While deplaning we called maintenance and filled out Report.  Flight attendants complained of symptoms so we called paramedics to aircraft.  Paramedics assessed flight attendants in jetway and elected to have them escorted to hospital for medical evaluation. Flight crew obtained a different aircraft and new flight attendants and departed for ZZZ1 almost 3 hours later.
A321 flight crew reported a fume event during preflight resulting in aircraft swap and flight attendants experiencing physiological symptoms.