I'm sure other owners of Golden Retrievers and other dogs have noticed this. When our two Goldens get happy by receiving love and attention from someone, the tops of their heads get really warm. At first we were concerned about this and asked our vet what this means. He explained that when the dog feels pleasure or "happiness", blood rushes to the top of the brain thru the Dorsal Sagittal Sinus, making to skin at the top of a dog's head, above the eyes get quite warm. This is often accompanied with tail wags, body wiggles and "Golden Speak", that crazy, silly whining they do.