paragraph: John wanted to have a birthday party for his son, Mike. John and his wife Sara knew that their son loved clowns, as did their daughter Jane. So they looked up a place to have a clown come to his birthday party. When the clown arrived, ten of Mikes friends showed up to watch the show. His parents had sent out 12 invites, thinking 6 or 8 kids would come. The clown started the show by squirting some water from a flower into John's face. This caused John's face to turn red. After the show, when everyone had left, it was up to John and Sara to clean up after the party. There was food everywhere; they had had salad and there was lettuce on the ground. Later that evening it was dinnertime and the family had to choose what to eat. The choices were order a pizza, make hamburgers, go get fried chicken or make noodles. Since it was Mike's birthday they let him choose. He really wanted pizza so they called up Pizza Palace to place their order. When the pizza arrived it did not come in a square box like most pizzas. Instead it was in a round box that no one had ever seen. John gave everybody a slice and then placed Mike in his lap to eat dinner. 
question: What caused John's face to turn red?
answer: The warmth in the living room