Cast iron cookware can become significantly hotter than ceramic or other types of metal casserole trays due to its unique heat retention and conductivity properties. There are two main factors that contribute to the high heat of a cast iron skillet:
Heat Retention: Cast iron has excellent heat retention capabilities. When you put a cast iron skillet in the oven, it absorbs and retains a significant amount of heat from the oven's temperature. As a result, even when you take it out of the oven, it remains hot for an extended period.
High Heat Conductivity: Cast iron is an excellent conductor of heat, which means it can quickly transfer the heat it retains throughout its entire structure. This property allows the entire surface of the skillet to become uniformly hot.
When you used an oven mitt to remove the cast iron skillet, the heat from the skillet transferred through the metal and reached the surface where you were holding it. Despite the oven mitt offering some protection, the high heat of the skillet overwhelmed the insulation of the mitt and resulted in a scalding burn on your palm.
In contrast, materials like ceramics have lower heat conductivity and typically do not retain heat as effectively as cast iron. So, when you remove a ceramic casserole tray from the oven with an oven mitt, it may still be hot, but it is less likely to reach scalding temperatures like a cast iron skillet.
To safely handle a cast iron skillet from the oven, it's crucial to use extra precaution. Consider using a thick and well-insulated oven mitt or even a specialized cast iron handle cover. Additionally, always be mindful of the skillet's heat and avoid direct contact with any part of your skin to prevent burns or injuries.