Toilet components that can tolerate hot water

I have a unusual situation with the toilets in my home, and I have searched around online but can't find any info on this. Basically I'm wondering if anyone can recommend toilet components that can withstand high water temperatures. On hot summer days the cold water comes out of the pipes scalding hot due to the pipes running through the attic which isnt vented well plus I live in fl. Every couple of years I am constanty replacing fill valves, drain valves, and all rubber components in my toilets because they cant take the 150f water temp. Ive been using the fluidmaster stuff available locally. Can any experts recommend a brand of fill valve, drain valve etc that uses some higher quality rubber that wont shrivel up with heat? Thank you