Why do dogs stick out their tongues when it's cold?

The most common reason why dogs stick out their tongues is heat dissipation. It is very hot in summer. Sweating can bring out the heat in the body through sweat, and the specific heat of water is relatively large. Dogs stick out their tongues to sweat, and at the same time accelerate sweat evaporation through exhalation, and stick out their tongues to increase surface area. Because dogs don't sweat and don't stop exercising because of the heat. The dog's body can't adjust its temperature, and the dog can't take care of itself and replenish water in time. The sweat glands of the dog are all on the tongue, so seeing the dog sticking out his tongue and panting means that the dog is very hot and needs to drink water to cool down or calm down. Don't move.