This is a pretty inventive way to warm up milk or formula. The Yoomi bottle will get you out of a hydration jam when you’re on the go and it’s impossible to even find a cup of hot water to stick the baby’s bottle in to warm. The caveat: it’s just not quite as easy as they claim.

It works like this: there’s a heating element that goes into the bottle. After 30 seconds, you turn the bottle upside down for another 30 seconds, and then you’re ready to feed. The milk passes through the chambers of the heating element and bingo! You get the right temperature every time without any guess work. But here’s the not-so-convenient part: you have to “recharge” it (that’s what they call it), but this means you actually have to heat it up by boiling it for 25 minutes. Once you’ve done this and it’s “recharged” you’re all set. It can then be used any time. You just have to remember to bring the heat when you leave the house (which is the only time I would consider this “convenient”).

They recommend buying several of these (of course they do!) so you always have one ready (the warmer by itself is $24). I recommend that you use it only when you’re out and about. Because when you’re at home it’s so much easier and better to just use my favorite warmer, Philips’ Avent, which is ultra-fast and foolproof. Yoomi at Giggle for $35.