12x24, but the wire cookie rack I used is slightly smaller, and some of the pad is draped to the floor. I started out with an under shelf basket, but it seemed like it was too tall for the first week or two. Then I searched like mad for your thread and it took me a week to find my way back to your instructions. (Not that I’m a good student…ugh). A *lot* of over thinking has been happening here! My husband wants to insulate the whole brooder box with cardboard around the outside. my gut says they will be fine, but my brain…
I don’t think we have an infrared thermometer, could I use the end of a meat probe?