you can put something between yourself and the floor, if its too rough say, or its a cold day, but usually no, i don't have anything
i live in a flat with old parquet and the wood gets warm quick when you lye on it, i never had any problems
you need some time to adapt if you do this first time or after a break, i was sleeping like that for decades, but in private house its better to put wood on bed or something, the floor can be cold and not as clean
the dirt/dust stops accumulating in the place you're sleeping for some reason