Hyperthermia is the elevation of body temperature, primarily in response to illness or environment. Excessive heat and humidity are a deadly combination for man and beast! This is especially true for dogs that are not acclimated to it.
Many are under the impression dogs do not sweat. That's not true. However, where and how much they sweat is not enough to cool them down when they are in distress. Dogs barely sweat the pads of their paws. A sign of an overheated dog damp paw prints.