My 9 week old is throwing his head and arms around moaning, he feels warm and he won't eat, I've…

My 9 week old is throwing his head and arms around moaning, he feels warm and he won't eat, I've only gotten him to eat 2 ounces since 6 this morning and it's now after 12. Usually he eats 4 ounces every 3 to 4 hours. Does anyone have any idea what could be wrong and what I can do? He sees the Peditrician tomorrow.