This IS going to turn out to be a joke, right??
WHY are you doing this Earlgrey? I mean, why did it start? What made you give into a request for uniform to be "put in the freezer" just once, in the first place?
Sorry but I think you are doing them a real disservice by allowing them to think it's ok to dicate to you in this way. Mother Earth I am not, I make all kinds of parenting mistakes daily I assure you.. but this is a problem you have allowed.. (if it's actually serious.. still doubting it tbh).
Just trying to imagine myself in the morning, juggling breakfast, medication, washing/dressing/attempting not to get beaten senseless by SN 6 year old, supervising physio of 14 year old, doing my makeup (my one fussy vanity!), checking for 6 yr old's school bus, etc etc.... and, making sure their uniform was the right temperature... ??!!!
Unless these children have autism I just don't understand this at all.