Even though dogs sweat like humans, their sweating process is entirely different from the latter. Man's sweat glands can be found in every corner of his body. However, a dog's sweat glands are only found on his paws and nose, making it difficult to tell when he's sweating.
When your dog pants, don't be bothered. This is his way of cooling himself down to maintain a stable temperature. He pants to release the warm sun in his lungs and inhale the cool air from his environment. Now that you know how vital panting is for your dog, stop preventing him from doing this action or discouraging him from panting. Once he stops panting, his body temperature will be affected.
However, panting alone is sometimes not enough for your dog to regulate his temperature. This is when you should enter. Assist him by wetting his coat with cool water. The cool water will help alleviate his body temperature. Bring him plenty of fresh water, and if possible, bring him to a cooler room or area in your house. Call your vet for assistance if he continues to pant aggressively after a few hours.