Sanding ,
The faster you sand the hotter things get
Do you need speed = No
If you obtaing a good Finnish straight from your tool then you only need a short period of time with each grade of paper .
I us a home made sanding pad , made from a old mouse mat , cut strips of sand paper , as you are sanding you can feel the heat starting to build up , Heat also causes micro cracking on some timbers , Slow speed and cautios aproch is the winner her , For me anyway
If it gets hot you have sanded for to long ( My opinion , others will disagree )