Aircraft was presented for service in a hot climate with an unserviceable APU. Cabin temperatures reaching high 30s and station staff proposal was to “board and get underway”. There is no upper limit for an acceptable cabin temperature for humans whereas I understand livestock do have limits. As such a number of us have researched the matter and deemed 25 deg is a reasonable limit. On this aeroplane it is possible to use the air start units to power the packs, but the station staff initially refused as it usually caused the air starter to overheat! Given the alternative of service cancellation, they ran it in ten-minute stretches which did reduce the temperature. Fuelling and most of cargo loading complete I decided to allow boarding as the station had ‘proactively’ loaded the customers to the jetty [without air-conditioning provided], against my instructions, and they assured me boarding would only take ten minutes.
Boarding took 25 minutes and later in the flight an elderly customer presented with symptoms of a heart attack, his wife suggesting he can get this associated with heat related stress.
