In the summer, it is not uncommon for children to have dehydration fever. Due to the need for heat dissipation, infants need to excrete a large amount of sweat every day to maintain a constant body temperature. Since the kidney function of infants is not yet mature, they cannot concentrate urine like adults to reduce water loss. Therefore, under normal circumstances, infants need 100 to 150 ml of water per kg of body weight per day. If water is not replenished in a timely manner, infants are prone to cellular dehydration, prompting an increase in body temperature. According to the measurement, for every 1 ℃ increase in body temperature, the body water can evaporate 10% more. In other words, dehydration can cause fever, and fever can aggravate dehydration, eventually leading to dehydration fever. In the summer, when the infant sleeps restlessly and cries for unknown reasons, parents should think that it may be caused by the infant’s thirst. If the baby is given some warm water immediately, the baby will soon calm down. Once dehydration fever occurs, parents should not panic, on the one hand, use gauze dipped in some warm water to wipe the baby’s forehead, neck, armpits, thighs, etc., for physical cooling; on the other hand, immediately give the baby oral 5% glucose water or warm boiled water, or feed some watermelon juice. For this kind of fever, taking antipyretic medicine is difficult to correct, only timely hydration, the fever can be quickly receded. Some young parents are inexperienced and always think that their babies are crying because they are hungry, so not only do they not feed their babies water in time, but they can’t wait to feed them high concentrations of milk, juice or sugar water. This can worsen the condition.