Our tableware and its Eco-Porcelain have a very high potential to accept huge thermal shocks. All of our items are tested. The resist to 5 subsequent chocks from -20°C to 100°C.
Our ceramics are willing to get high thermal shocks; the most important is to get those chocks even. Do not put just the edge of a very hot item in ices, it will break. You can put the full item in the ice, it will easily resist the thermal shock.