Do not put a spoon with strained food onto your arm to test temperature and then into the baby's mouth. Do not stick your finger into the jar of baby food or test it with the tip of your tongue. Test by the temperature of the container or of a sample dripped onto your wrist or inner elbow. Do not warm baby's food in the microwave oven. Microwaving may leave hotspots in the food, so that one spoonful of food may be cold, while the next spoonful may burn baby's mouth.
Babies accept cold or room temperature foods, making warming unnecessary.
If you do need to warm food for babies, do so carefully, and stir the food to even the temperature. If an infant falls asleep while feeding, and an adult is not present to remove the bottle, milk may remain in the mouth during sleep. The sugar naturally found in this milk can cause cavities in new or forming teeth. Teeth with cavities may hurt or break, making it difficult for a child to chew. Inability to chew makes it difficult for children to get the calories and nutrients they need.