Megabus nightmare?

My son is at this moment, (3.20pm) on a megabus coach travelling from Preston to Glasgow. It was an hour late arriving at Preston and will not reach Glasgow until after 7pm now. The problem is the air conditioning is not working. The weather is sunny and the windows don't open, and the customers are all boiling. My son says he has never felt heat like it and hes only been on the bus about 40 mins. I phoned their customer services to make sure they stop at Services and Megabus provide cold drinks to keep people from becoming unwell, but the wimpy girl on the phone said she doubted they would do that! Help, is this legal?????