Build outside of case

[Sandycheeks]

When putting components together and testing on top of motherboard box is it ok to do this for the length of time it would take to install OS and updates, say a couple of hours or would it get too hot.

 

[Sandycheeks]

Google, Motherboard Testing Switch Set, amazon have them, very handy.

I have one of those...it's called a screwdriver