Ask any high school teacher- the proposed schedule change is not a good one. If the catalyst for this potential change is that elementary school students can't handle the heat- then fine, elementary school can start later. But ask ANY high school student- they don't want to take finals after break. Please. No one will be able to study enough to make up for what they forget over break. When the parents of the elementary students have kids in high school, they will understand- WE NEED A BREAK. High school is a huge challenge! The pressure of looming finals takes away the relaxing part of break.
Ask the teachers- how will they teach with a short semester and a long one? How would semester long classes work? Especially semester long AP classes.
LEAVE THE SCHEDULE and don't try to change what already works just fine.