By Mark Peifer, USA Pickleball Certified Referee; Past Chairman, USA Pickleball Rules Committee
QUESTION: If the ball hits your hand while you’re returning a volley, is that a foul?
ANSWER: The answer to this question is found in Rule 7.H of the Official USA Pickleball Rulebook. The Rulebook is provided for free at this link: https://usapickleball.org/what-is-pickleball/official-rules/
Your question was specific to a volley. If a live ball hits you anywhere on your body, it is a fault, regardless whether it was a volley. There is one exception to that rule, however.
The only part of the body that can be hit by a live ball and not be a fault is the part of your hand below the wrist as long as that hand is in contact with the paddle. In other words, it is not a fault if the hand in contact with the paddle is hit somewhere between your fingertips and your wrist.