It is vital for students to get into simple and absolutely fixed routines within school, where the process is itself a routine, i.e. what students wear and how. This frees up cognitive overload (the brain being unable to process more information as it is at capacity in the working memory) allowing students to be more open to learning and decision making. In addition, if the routine is established then there is no confusion, no need to add to communication and it prevents subgroups of students exerting influence over other students to get them to follow, actions which can lead to bullying.
Therefore, we insist on building those routines from day 1 and sticking to them. Students have been allowed to remove their blazer at any time during the day, except in assemblies. Assemblies are formal occasions, deserving the respect of formal attire and the room is air conditioned.Many students have chosen to continue to wear them despite the weather, at their discretion.