Signs your dog might be too hot extend beyond just excessive panting. Watch out for signs of discomfort like excessive thirst, heavy drooling, or loss of energy. More serious symptoms could include vomiting, diarrhoea, and disoriented behaviour. A dog's normal body temperature ranges between 38.3°C and 39.2°C (100.9°F - 102.56°F). If you'e worried about your dog, please seek veterinary advice.