Boys to wear shorts in hot weather in school

Im starting this petition as my son
was discriminated by pencoed comprehensive school for wearing shorts on 19/06/2017... today was 28 degrees, I was told that josh would have to wear black trousers provided by the school to change into! I was not happy about this, also I went into the school as I was told by josh he was not allowed to go to.lessons because of this shorts business! summer dresses with wedge shoes, linen trousers with sandels, school girls in tight short skirts, but the boys in trousers, this is unacceptable due to the heat , I was then told my son would have break but not with the other kids! This is discrimination without fail, all because he wore shorts in hot weather, I didnt not realise wearing shorts to.school would affect their learning... give the boys the option of wearing shorts or trousers on hot days!