All of this pursuit of light weight backpacking has people figuring out what they can possibly leave behind to keep weight down. I get it. But one thing I have to wonder is how people manage to travel without any change of clothing whatsoever for hikes of 3 or more nights. I am particularly concerned about underwear.

Just in normal outdoor daily activity I find that getting sweaty irritates me to the point that I would not even think about not changing the boxers. And yet I have read more than enough light and ultra light lists of gear that advocate not carrying any extra clothing whatsoever even for longer hikes.

How do people deal with this situation? Am I unusual in needing to take care of hygene in that area? I know that everybody seems to be resigned to having plenty of BO after multiple days of hiking. But it is one thing to smell and another thing to have your hiking get painful due to irritation.