My son who is nearly 4 attends a local pre-school within a private nursery and their summer 'policy' is that children must wear long sleeves, have socks on, leigonnaire hat and sun cream on.
I do all of the above except the long sleeves (purely because i can not find any for sale that are summery and are within my budget) the only lobg sleeve white cotton thing i can find is a school shirt...which i have got for him and put this in his bag (but looks silly on him as is really smart)
Therefore i send him with short sleeves that cover his sholders.
The pre school staff have pulled me up on this several times. I tell them that i am worried about him overheating
Anyway the last few times i have collected him the preschool have made him wear his hoodie jumper. The temperature has been mid 20's. When i have collected him he has been obviously hot- i.e. clammy, red faced and feeling very hot. Yesterday i collected him and he told me he didnt want to wear it but one of the staff members told him he had to.
Prior to that the preschool had put on one of his winter long sleeve tops which must of been in the bottom of his bag... it was dark colour and thickish material...this was on a day when it was nearly 30 degrees outside.
I am fuming that they let him clearly over heat.
The staff dont lead by example and are usually there in shorts and a nursery polo shirt. 
I dont know weather to raise this with the nursery/preschool owner or ofsted or something similar... what would you do?
Thanks in advance