Me? Not immediately.
It is pretty likely my children will know what I look like nude, my wife also.
Questions would be asked, I would answer. Unless the nude person is performing some act sexual in nature I cannot see the immediate harm in this particular scenario.
If the nude person has ill intent this is a problem.
If no harm is obvious I would likely be laughing at the oddness of it all, then answering questiosn about why someone was nude in public at the playground. Then, "why can't I be naked at the playground?"
"You can't be naked at the playground because people get very offended." my answer would be.