My 4mo kitten is harness trained, and we took him for a walk on a nearby trail today. About 20 minutes into the walk, he started panting. We immediately turned around to go back to the car, and picked him up. He didn’t want to be held, and wanted to keep walking. He continued to pant the whole car ride home, and refused the water we tried to give him. Once we arrived home, he ate, groomed himself, then took a long nap. He seems perfectly fine now. He’s being very playful, and he’s eating. It was about 68°F today and sunny. Could he have been too hot? Or is this something I should contact the vet about?