I think there is a maximum number of hours you're allowed to sit in one day (it's what I heard, but don't quote me on it). If your exams clash or it goes over the maximum, one of your exams may be moved to another day.
Ask the exams office in your college/school for details, but when you sit your exams is quite strict, so probably not.
You will put into isolation and take the exams 1 after another. I have previously done 3 GCSE exams in one day but I've never heard of someone having 4 exams in a day.
I've been told by a teacher that in extreme cases a student may have to stay at a teacher's house over night and then take their exam(s) the following day, this is obviously necessary to keep you in isolation. I can imagine with 4 exams that this may be a possibility as it would be unreasonable to expect you to take them all in the same day.
My summer timetable also sucks though not as bad as yours does. The exam boards need to get together and co ordinate it so that similar subjects aren't placed close together on the calender. For example, don't have all the science unit (x) exams in the space of 2/3 days.
Thanks for your help. i spoke to my exam office at school and i have 2 possibility's.
1) Take 1 exam the following day - This means only one exam can be taken the next morning and i have to be under monitor throughout the whole day and night including mobile phone checks, email/internet checks, house phone checks, parents under monitor... and there is alot of paper work to do,and all exams are back-to-back
2) Take all 4 exams on one day and make a special consideration. This means that i can choose to sit my exams in any order regardless of the times, however, on my paper that i decide to do last, i will have a special consideration, which means that the paper will be marked generously. With this option, i can have upto 1 hour break between each exam.