USING EMER COMMAND AUTHORITY; AN ACR CREW DEPLANED PAX ONTO AN OPEN RAMP DURING AN EXTENDED WX DIVERSION GND DELAY BECAUSE THE APU DID NOT COOL THE ACFT IN HOT WX WITH PAX ON BOARD.

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AFTER AN EXTENDED PERIOD OF TIME IN A HOLDING PATTERN DUE TO TSTMS IN ZZZ1; WE DIVERTED TO ZZZ2 TO WAIT OUT THE WX AND TO REFUEL. WHEN WE LANDED; THERE WERE SEVERAL OTHER AIRPLANES ON THE RAMP THAT HAD ALSO DIVERTED TO ZZZ2 FOR WX. WE PARKED ON AN FBO RAMP NEXT TO ANOTHER DIVERTED JET; AND WAITED OUR TURN FOR FUEL. BECAUSE ZZZ2 IS A SMALL ARPT WITH FEW FUEL TRUCKS; WE HAD TO WAIT SOME TIME FOR SVCING. WHEN WE FINALLY HAD OUR NEW FUEL LOAD ON BOARD; WE BEGAN TO MAKE PREPARATIONS FOR THE SHORT FLT BACK TO ZZZ1. WE CALLED THE GND CTLR AT ZZZ2 AND WERE TOLD THERE WAS A SIGNIFICANT DELAY DUE TO FLOW INTO ZZZ1. WE THEN CONTACTED OUR DISPATCHER AND WERE TOLD THAT ZZZ1 WAS CURRENTLY NOT ACCEPTING ANY AIRPLANES DUE TO A GND STOP. WE MADE ANNOUNCEMENTS TO THE PAX ABOUT THE ATC DELAYS AND WX SITUATION WHICH WAS CAUSING US TO SIT ON THE RAMP LONGER THAN EXPECTED. AS OUR DELAY ON THE GND CONTINUED; WE STARTED TO RECEIVE CALLS FROM THE FLT ATTENDANTS; TELLING US THAT THE TEMP WAS GETTING VERY WARM IN THE CABIN AND THAT PAX WERE BECOMING UNCOMFORTABLE. THE FORWARD L1 DOOR HAD BEEN OPENED FOR ACCESS TO THE RAMP FOR PREFLT; AND TO GET PAPERWORK FROM GND PERSONNEL. IT WAS A HOT AND HUMID EVENING IN ZZZ2; HOWEVER; SO WE KEPT THE FORWARD DOOR CLOSED UNLESS RAMP ACCESS WAS NEEDED. FOLLOWING THE CALL FROM THE FLT ATTENDANTS; WE CHKED THE STATUS OF THE PACKS AND TRIED VARIOUS SETTINGS WITH THE PACKS TO MAKE THE CABIN TEMP COOLER. THE APU HAD BEEN STARTED ON TAXI INTO ZZZ2 AND WAS GIVING NORMAL PRESSURE INDICATIONS. HOWEVER; THE CABIN TEMP WAS NOT DECREASING. TO ASSIST WITH COOLING THE CABIN; WE CALLED OPS FOR A LCL ACR IN ZZZ2 AND ASKED ABOUT OPTIONS. SINCE THEY USUALLY SVC SMALLER ACFT; THEY HAD NO MEANS OF PROVIDING SUPPLEMENTAL CONDITIONED AIR TO OUR ACFT. BECAUSE THE CABIN WAS SO HOT; AND NOT COOLING DOWN; WE ASKED ABOUT AN AREA WHERE WE COULD DEPLANE THE PAX. WE WERE TOLD BY AN ACR AGENT THAT THE TERMINAL WAS UNDER CONSTRUCTION AND THERE WAS NOT ENOUGH ROOM FOR OUR FULL PLANELOAD OF PAX. THE AGENT HAD ALSO SPOKEN TO OUR DISPATCHER ON A CELL PHONE ABOUT THE LACK OF TERMINAL SPACE. THE DISTANCE FROM WHERE WE WERE ON THE RAMP TO THE AFOREMENTIONED TERMINAL WAS ALSO SIGNIFICANT SINCE WE WERE OUT ON A REMOTE SECTION OF THE RAMP. BECAUSE THE TEMP IN THE CABIN WAS BECOMING INTOLERABLE; AND THERE WAS NO IMMEDIATE PLACE FOR THE PAX TO GO; THE DECISION WAS MADE TO START AN ENG TO TRY TO HELP THE AIRFLOW AND TEMP SITUATION. THE L ENG START WAS ATTEMPTED; HOWEVER; THE START HAD TO BE ABORTED DUE TO A STARTER LIMITATION AND LACK OF SUFFICIENT AIRFLOW FROM THE APU. AT THIS POINT; THE FLT ATTENDANTS TOLD US THEY WERE WORRIED ABOUT THE HEAT AFFECTING SOME ELDERLY PAX; AND A PREGNANT PAX. SEVERAL OTHER PAX WERE DEMANDING TO GET OFF THE AIRPLANE. TO PREPARE FOR ANY POTENTIAL HEAT-RELATED PHYSICAL CONDITIONS; WE CALLED FOR MEDICAL PERSONNEL AND FIELD OFFICIALS. WITHIN MINS; THE FIRE DEPT; AMBULANCE; AND ARPT POLICE SURROUNDED THE FRONT L SIDE OF THE AIRPLANE. HAVING VERY FEW OPTIONS; THE DECISION WAS MADE AFTER CONSULTATION WITH DISPATCH; TO DEPLANE THE PEOPLE ONTO THE RAMP BECAUSE THERE WAS NO AVAILABLE TERMINAL BUILDING; NOR ANYWHERE ELSE TO HOUSE THEM ON THE ARPT. THE PAX WERE NOW STANDING IN A SUPERVISED AREA; CONTAINED BY THE ARPT PERSONNEL AND VEHICLES. THE TEMP OUTSIDE WAS DECREASING AS EVENING FELL; AND PEOPLE WERE ABLE TO GET SOME RELIEF FROM THE HEAT. WE CONTINUED TO COORD WITH DISPATCH; THE LCL ACR AGENT; OUR FLT ATTENDANTS; AND ATC. DURING THIS TIME; THE ACR RAMP WORKERS WERE FINALLY ABLE TO PROCURE A SMALL AIR CART FOR ENG STARTING. THE DECISION WAS MADE TO ATTEMPT TO START THE R ENG WITH THE AIR CART IN ORDER TO HELP TO COOL THE CABIN AND MAKE THE TEMP SUITABLE FOR OUR PAX TO RE-BOARD. KNOWING THAT THE GROUP OF PAX WAS CONTAINED ON THE RAMP AT THE L FRONT END OF THE AIRPLANE; THE R ENG WAS STARTED SUCCESSFULLY. HAVING AN ENG PROVIDING AIRFLOW TO THE PACKS ALLOWED THE CABIN TO COOL. WE RE-BOARDED THE PAX ONTO THE AIRPLANE; AND WHEN EVERYONE WAS SEATED WE AGAIN BEGAN PREPARING TO DEPART FOR ZZZ1. WHILE WE WERE COORDINATING A DEP SLOT TIME WITH GND CTL IN ZZZ2; WE RECEIVED A MESSAGE FROM OUR DISPATCHER THROUGH ACARS. IT WAS NOTIFICATION THAT THE CAPT AND I WERE ABOUT TO REACH OUR DUTY LIMIT FOR THE DAY; AND WE WERE NO LONGER ABLE TO OPERATE THE FLT TO ZZZ1. WITH NO OTHER OPTION; IT WAS DECIDED THAT WE WOULD TAXI THE AIRPLANE OVER TO THE TERMINAL RAMP AND ALLOW THE PAX TO DEPLANE INTO THE TERMINAL BUILDING. THERE WERE SEVERAL REMAINING ACR AGENTS WHO ESCORTED PAX FROM THE AIRPLANE INTO THE TERMINAL WHERE THEY WERE PROVIDED WITH WATER AND REFRESHMENTS AS THEY AWAITED FURTHER INFO.