Dogs need to drink normal temperature water in winter, and are not suitable for drinking hot or cold water. If they are in some very cold areas, or the room temperature is very low and the drinking water becomes cold, the water can be heated to 20 degree or above. Sick dogs, puppies, and elderly dogs need to be fed warm water above 20 degrees.
There is no need to deliberately change the temperature of drinking water according to the weather. Whether it is hot or cold water, water and food with abnormal temperatures can easily irritate the dog's gastrointestinal tract, causing gastrointestinal discomfort and various problems. If you are in some very cold areas, or if the room temperature is very low and the drinking water becomes cold, you can heat the water to more than 20 degrees. The same principle applies to feeding. Do not eat food that is too hot.
For puppies, it is best to switch to warm water in winter, because when the puppy drinks milk, the temperature of the milk is the body temperature of its mother. Giving cold water directly to puppies will greatly irritate their intestines and may cause them gastrointestinal discomfort.