If you are currently formula feeding your little one every few hours through the night... here is an easy trick to get you through those late night feedings.
After a feeding, heat a full kettle of water up on your stove. Next, pour some of the hot water into a bottle--but fill it approximately an ounce or two less than what you are going to use to mix up the next bottle--and set this bottle aside. When your little one wakes up for the next feeding, top up the bottle with the water from the kettle. The water in the kettle will stay warm for approximately 3 - 4 hours.
There you have it: instant warm water for the formula without waiting for the bottle warmer to heat up. In the middle of the night, when your little one is crying for food, you can reduce the waiting time by several minutes.