THose things are eant to be used at much higher temps, on a regular basis. 223 degrees shouldn't affect it, in the least. They ARE cast aluminum, though, which does *tend* to warp. I'm thinking this might happen more from it cooling too fast, rather than getting too hot. I could also see where the spigot might make it cool unevenly, too. I wonder... is your work area really cold, most of the time ? Did you wipe it off with a damp rag, on the outside ? Top may have some more/better ideas. Maybe he'll check in, soon.