user19238: Are there regulations on what to do when your opponent has poor hygiene and it negatively influences your performance?
I do not want to be disrespectful or shame anyone, but bad breath or body odor really can negatively impact your mind, especially if you have to spend hours opposite of the person. It is not fair to have to play under such conditions (in my opinion).

user18809: Unless the tournament organizer wants to do something aobut it, I am afraid you will have to deal with it. Theoretically, FIDE rules prevent these situations from happening, but in practice, you have no real power to enforce them by yourself

user4418: According to Article 12.2.3 of the FIDE Laws of Chess it is one of the roles of the arbiter to -

12.2.3 ensure that a good playing environment is maintained

Your first course of action should be to bring the matter to the attention of the arbiter. It is not a pleasant thing for him or her to deal with but it is part of the (usually unpaid) job of the arbiter to resolve such problems.

19238: <p>Are there regulations on what to do when your opponent has poor hygiene and it negatively influences your performance?</p>

<p>I do not want to be disrespectful or shame anyone, but bad breath or body odor really can negatively impact your mind, especially if you have to spend hours opposite of the person. It is not fair to have to play under such conditions (in my opinion).</p>
 18809: <p>Unless the tournament organizer wants to do something aobut it, I am afraid you will have to deal with it. Theoretically, FIDE rules prevent these situations from happening, but in practice, you have no real power to enforce them by yourself</p>
 4418: <p>According to Article 12.2.3 of the <a href="https://www.fide.com/fide/handbook.html?id=208&amp;view=article" rel="noreferrer">FIDE Laws of Chess</a> it is one of the roles of the arbiter to -</p>

<blockquote>
  <p>12.2.3 ensure that a good playing environment is maintained</p>
</blockquote>

<p>Your first course of action should be to bring the matter to the attention of the arbiter. It is not a pleasant thing for him or her to deal with but it is part of the (usually unpaid) job of the arbiter to resolve such problems.</p>
