The carers are probably just as cranky as you! If not moreso as they are working in 40 degree heat and trying to keep all those toddlers entertained in that heat UGH! Yuck! Not my idea of fun that's for sure, especially for less than $20/hr!

Write your complaint letter, say pretty much what you have said: I feel sorry for them having to deal with all the whingy toddlers in this heat as well but I feel like an explanation should be given and an action plan should be in place. Say that you don't think that toddlers should have to be in this heat ESPECIALLY if the other rooms have air con, and that the carers should have it too! Hopefully this is what they need to take to management to get aircon in the room