Page 2 | Freezing school

My son is taking his mocks this week and next and I'm concerned that he's doing them in an absolutely freezing hall without any heating. He's the sort of person who is normally always hot but he's coming home chilled to the bone. He's doing 2 exams a day in there plus 2 hours revision so 6 hours per day in total. The supervising staff are walking around with big coats on! It's a private school and I've emailed the headmaster to say the temperature isn't adequate and it's affecting my sons concentration but I've not had a response yet. What else can I do? I feel like I don't want my son going in the hall next week if conditions aren't improved but I obviously don't want him to miss his mocks.