For the water temp I use it straight from the tap right away, so I would believe that it wails be fairly close to the same temp as the air in the house, or at least close. But it could have been enough to stress it far enough to crack. The only difference that I know of is I generally soak the stone before using it, the last time using it I was only wetting the top. Which when put away one side dry and one side damp. This stone really doesn't absorb much water at all.