That being said, I've always given my kids 3rd quarter off. I think they deserve the break. I generally ask our kids to be back in the stands by "2 or 3" on the clock in the 3rd. Sometimes we play then, but generally, that just gives us time to be ready to play the entire 4th quarter.
I understand the student safety concerns others mentioned. At my small school, I just really don't have that concern. We have all administrators at games plus 2 SRO's and a ton of teachers and parents. If I were at a larger school, that might be different.