I notice that when I reheat food in a microwave (such as last night's casserole) it doesn't retain its heat as long as it would when reheated conventionally.
I agree with Society. How long are you heating it for and on what power? I would do a casserole in a 3 pint dish half full for at least 7 - 10 minutes on medium until it is really bubbling all over. Your microwave cookbook with the cooker should give you a guide.
I did wonder about putting it in science.....think I will do it now.
Everything is bubbling hot when it comes out, meat is hot right through, but as soon as it goes on to the plate, there seems to be a much quicker cooling. Thanks for your thoughts. I'll see what the science people make of it.