I know a young lady who is going to college to be a teacher for special need children and she volunteers at a class with children with autism. She told me that changing from one activity to another without notice or time to prepare is indeed very disturbing and stressful to the child with autism. If this group of kids is going from one activity to another, you may want to prepare your little angel by telling him/her what is about to happen in advance, for each and every activity. She does this and from what I understand, it helps tremendously.
Cootie