Over 85 your rats will start produce very little (basically your cost will skyrocket feeding the breeder while having little to no production, and I am pretty sure if you want to breed rats that's because you want to save money)
At over 90 you will start seeing rats dropping dead randomly.
Not right now however it will be and we are talking about the possibility of losing your colony entirely if that is not controlled either.*edit: I know about outside breeding might attract other rodents \ predators to them but that not my problem right now*
Basically as it stand your colony is doomed to fail, might as well keep buying food.
You need a shed in which other rodents that can pass on parasites and diseases cannot get in and you need a solar panel that can power a big fan at the very list to cool the animals and keep the air moving, in addition I would also recommend a solar exhaust fan.