Do not use a microwave oven to heat the bottle because microwave ovens can create hot spots in milk or formula. Test the nipple by pulling on the bulb portion, and replace if nipple shows any signs of wear. Wash all parts prior to use. Do not let a child take a bottle to bed or self-feed for long periods. Allowing your child to use this product for prolonged periods separate from regular mealtimes or to go to sleep while drinking liquids, other than water, from this baby bottle may cause or contribute to early childhood tooth decay. Always test temperature of liquid before feeding baby.