This is a safety issue. Although microwaves are convenient, they can heat liquids unevenly. As a result, there may be hot spots that can burn your baby's mouth — even though the outside of the bottle or a few drops of the liquid may feel only warm.
Many babies prefer warmed bottles of formula or breast milk. But feedings don't have to be warmer than body temperature. Most babies do just fine with feedings warmed to room temperature. Older babies may readily drink cold liquids.
The best way to warm a bottle is to place the filled bottle in a bowl or pan of hot water and let it stand for a few minutes. Shake the bottle after warming it to distribute the warmed milk evenly. Then turn it upside down and allow a drop or two of the liquid to fall on your hand or wrist. It should feel comfortable or barely warm.
If you must use the microwave method, follow these precautions:
- Keep the bottle upright and uncovered (no nipple) during heating to allow heat to escape.
- Heat 4-ounce bottles at the high setting for no longer than 30 seconds and 8-ounce bottles for no longer than 45 seconds.
- Turn the bottle upside down at least 10 times. This evens the temperature difference between the top and bottom and eliminates hot spots.
- Always test the formula's temperature before feeding it to your baby. It should feel cool to slightly warm.
If you need a bottle warmed in a restaurant, ask how they warm baby bottles. If they use a microwave, you'll want to follow these same precautions.
