What are the halachic requirements for both men and women in regards to tznius, that is covering the body, specifically regarding the arms (shoulders downward) and legs (knees downward). In what ways if any are these requirements lessened when it comes to bathing and sleeping?
Answer:
For men there is no obligation of tznius in covering these parts – though for davening one should be careful to dress in a respectful manner.
For women arms down to the elbow must be covered in public, the Mishnah Berurah writing severely about the immodest practice of not doing so.
There is no obligation to cover the legs from the knee downwards, though where the custom is to wear socks one must do so. For purposes of Keriyas Shema (of a man who can see the woman in question) there is a debate concerning this between the Mishnah Berurah and the Chazon Ish. The general custom is to rule leniently.
These principles do not apply while bathing, which is of course done in private; there is likewise no obligation of covering up during sleep — though there remains a virtue of observing tznius practices even in private areas.
Best wishes.
