These glasses are good quality stackable tough. I had a hot raspberry tea with honey in this glass, stirred with Dutchess spoon, the spoon didnt get too hot to stir and the glass didnt get too hot to hold. Ive never poured a hot tea in a glass ever,  but this withstood a boiling tea. Im impressed.  And whats nice about having raspberry tea in a glass is the nice red color you see through the clear glass. These glasses are functional and beautiful. Absolutely no regrets.