[Q] How to reduce heat in M7

Hello Mates,

I just recently took over my girls' M7. Love the phone. I recently updated it to the lollipop factory ROM and now the phone is very hot. What can I do to reduce the temperature? I have Disabled many apps, since i'm rooted, i installed Greenify. But is there anything else? Perhaps an optimized kernel designed for this?

Thanks for any feedback,

Paul