A319 First Officer reported high temperatures in aircraft cabin with a passenger overcome by heat. Captain selected 'Hot Air' switch to off and cabin cooled slightly.

Narrative

During cruise; the flight attendants called multiple times to tell us [know] that the temperature in the rear of the aircraft was very hot. The Captain turned down the temp controllers more and more after each call; eventually turning them to full cold. The aft temp display in the cockpit showed the temperature dropping; but the flight attendants kept telling us that the temperature in back hadn't dropped at all. The Captain had looked through our manuals but found no set procedure for such an incident.On our descent into ZZZ; perhaps near ZZZZZ intersection on the ZZZZZ1X arrival (possibly closer to the airport as we were getting handed off to ZZZ Approach); the Flight Attendant (FA) called to tell us that a woman was overheating and requested EMTs at the gate. There were no medical professionals onboard. The Captain turned off the Hot Air switch and the plane began to cool down a bit. We then [requested priority handling] and were given Runway XXR and an expedited taxi to the gate. The lady walked off under her own power and the EMTs took it from there. No further issues.A similar issue had been previously reported but was not on MEL as far as I can recall. The temperature sensors were not giving correct info to the cockpit display.