Sweet....I've never really thought much about it. I use what they give me and don't spend much time worrying about it.
After a long run I've been know to strip down (pre shower) and lay on the bedspread (until I cool off and shower).....
And after all these years I've never had a problem (I also don't put down the paper toilet seat

and have never heard of anyone getting anything from sitting down)
annerj -I think people worry to much about the small stuff-