Commercial Fixed Wing
Flight Attendant Current
Confusion; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Company Policy; Human Factors; Environment - Non Weather Related
My inbound crew was delayed due to weather; customs; and CA request [for] a meal break. FAs arrived at approx XA:30 and FD arrived at XA:45.  Paperwork indicates flight was closed at XA:35. Standby FAs told us they were called and when they advised the agents the plane was too hot; they were told they must board and passengers said they boarded on time.  There was minimum power (lights only) NO AC and NO air circulating.  Passengers were fanning themselves; perspiring profusely and said they had been waiting for about 45 minutes.   The CA said it was 27 Celsius onboard which may meet the standards to board;  but not to sit on a full (including X children) plane for an extended time.  When I asked the agent if he had checked the onboard temperature; he said he had no way to do that.  2 Managers (did not introduce themselves) later came onboard and said the plane was hooked up to the APU; and I suggested they talk with the passengers about their experience.  I later saw the agents on the bridge with what appeared to be a temperature gauge.  My concerns are (1) our passengers were needlessly made to sit on a hot plane. (2) Pre-boarders expressed their concerns and they were ignored; and (3) the plane was full so there was no social distancing.
Flight Attendant reported that passengers were boarded onto an aircraft that was too hot.