we live in florida do you guys think it is probably just the heat and him not drinking enough water or is it something i should be worried about? he has no other symptoms
How about mould in the school? If he is not complaining about headaches when he's at home... and only when he is at school... then there has to be either something in the air there, or perhaps he needs eyeglasses and has a tension headache from straining his eyes?
I doubt its serious, probably just dehydrated, could be stress, and heat as well. If it keeps up, take him to the doctors, and get them to do a catscan on him. Chances are it's nothing, and at worst its likely low iron or BP. If thats the case the doc will give him medicine for it.
It could be the heat and a hydration problem. There is so many different things that could be causing the headaches. If they happen around the same time there is something in particular that is causing them. Since they are reoccurring, I would have him see a doctor. Only a trained professional could determine if this is something threatening or not.