Heatstroke Awareness Warning signs of heatstroke: Is the dog panting heavily? Is the dog drooling excessively? Does the dog appear lethargic, drowsy, or uncoordinated? Is the dog collapsed or vomiting? What is heatstroke? If dogs are too hot and are unable to reduce their body temperature by panting, they will develop heatstroke which can kill. If a dog is displaying any signs of heatstroke, move them to a cool, shaded area and call a vet immediately. Some types of dogs are more prone to heatstroke, like very old or young dogs, dogs with thick, heavy coats, or dogs with very short flat faces like