When a child has a high fever, hot water should be used for physical cooling and cold water should be avoided as much as possible. The application of cold water for physical cooling will often cause the child’s skin surface to feel the temperature difference very large, thus stimulating the emergence of chills. Chills in children can cause fever to become more pronounced, which is not conducive to the reduction of high fever. The application of hot water can effectively play a physical cooling effect by evaporating water to reduce the heat. And using hot water to physically cool children will not cause chills and other uncomfortable symptoms. However, the temperature should not be too high when applying hot water, about 42 ℃ can be controlled, so it is more appropriate to apply hot water when children have high fever.