Hello. Thank you for sharing your feedback on the Calphalon® Stainless Steel 10-Piece Tri-Ply Cookware Set. We are sorry to hear that the cookware began to warp and that you ultimately had to return the set. We understand how disappointing this must have been, especially since the set was purchased as a gift for your son. To help prevent warping, we recommend avoiding sudden temperature changes, such as placing hot cookware directly into cold water, and allowing the cookware to cool before washing. We appreciate you taking the time to share your experience. Your feedback regarding the durability and warping of the cookware will be shared with our team as we continue reviewing our products and customer experience. If you have any more feedback, please reach out to us via our Contact Us form on our website. We’re available Mon.-Fri. 9am - 5pm Eastern Time. Thank you! Calphalon® Consumer Care