A bath should be a pleasant experience for the dog. A dog's internal temperature is higher than humans. The normal range falls between 38°C to 39.2°C. Hence, it makes sense to conclude that the dogs would be even more sensitive to cold water than humans.
Cold water is no fun for most dogs. It can chill your dog. Plus shampoo doesn’t usually work as well in cold water.
Another disadvantage of bathing your dog with cold water is that there will be a risk of it getting a “limber tail” which is also known as “cold water tail.” It is a very painful condition that will cause dogs to hold their tails between their legs, and they usually react sharply if you try to touch the tail. There is not much known about what actually causes this condition, but it is suspected that somehow the muscles at the base of the tail become paralyzed temporarily by the cold water. Fortunately, dogs will eventually get over this condition on their own, but in the meantime they should be given pain medications.
Majority of them would prefer a nice warm bath. Test the water temperature before beginning to wet your dog’s coat, it should be lukewarm. Keep your hand in the water to make sure the water temperature remains correct.
The dog skin is different from ours, so hot water can burn dogs more easily. Bath water should never be hotter than what you would run for a human baby. Keep it even cooler for large-breed dogs because they can easily overheat.
However, common-sensically speaking, if the weather is very hot outside, you could use cool (not cold) water instead, which can feel very good to a dog. If bathing outdoors, please do so only on hot days with no chance of cold changes so that your dog won't catch a cold.
In conclusion, wherever you choose to bathe your dog, indoor or outdoor, you should always use lukewarm water to bathe them. It is more comfortable for the dog, better for their skin and forces more dead coat out in each bath.