Keep rats outside

[Scherf]

Hey there,
I keep my rats outside, how can I be sure as much as possible that they will survive the hot summer days?
I do not have access to electricity outside so I can't use any a/c nor fans...
At August the temp can reach 86-95F I know the breeding will stop a bit yet I don't want them to die.
There any method I can help them survive the hot summer days without the option of a/c \ fan? I really can't get any electrical power outside...
The rack system at the shade tho

*edit: I know about outside breeding might attract other rodents \ predators to them but that not my problem right now*

I do believe anything over 80 can be killer, the reason my bell is ringing to that number is i know i will have to put AC window unit in my garage. on a 75 degree day, my garage can get to the 80's no problem.