Heaterz Flameless Heater Magic Oven Bags for Camping, MRE's & Hiking ~ Pack of 10!

Yes, they warm up, but make sure you have about 30-45 minutes to wait for them to reach their full potential. These take FOREVER to even start warming up. My wife and I have a baby and sometimes we caught out in public with a hungry/crying baby, cold milk and no way to warm it. I imagined that they would be just like the MRE heaters that I used to use in the Army; but they are not. I bought these to use as bottle warmers when we have no access to a electricity or a microwave to warm our baby's milk. They would have been the perfect solution if they had warmed up faster. I won't buy anymore of this brand.

Put them in bag and fill to water line with water and absolutely nothing happens. Disposed of first one and tried with another. Guess what? Nothing again. Read the directions again thought maybe I had a brain fart. I have us USGI ones and never had a problem. So I tried all four packs in one bag since I got ten bags and ten packs. I also tried ripping one one pack off and putting it in bag and again NOTHING. Conclusion! Rip off! There junk,,,do not waste your money. Remember! The U.S.A. has spent billions even trillions over the years on R&D. Stick with USGI products for any prepping needs. These after market rip offs are a waste of money. GOOD LUCK!

These things are great for backpacking hiking or camping. Requires food packaging for either "boil in bag" some "microwaveable" or MRE packages to cook

I added water and nothing happened. I waited . . . still nothing. I came inside and threw them in the trash. Then a few minutes later I heard a sizzling noise. The heaters were working. So I tried again. Went outside, added water, nothing happened. Then I remembered my chemistry and past experiences with hand warmers - reactions only happen when the temperature is high enough. 35 degrees outside and nothing happened, 68 degrees inside and the reaction proceeded well. So if you want to heat up a meal when it is already reasonably warm, these will work well. But if you are hoping to use them in the winter some place cold, I do not think these will work unless you use your own body heat to warm everything up to get the reaction started.

Don't add too much water and these are fantastic! I think the other poster used too much water as we haven't had a problem with them working when we winter camp. If you have a small cooler (think 6-pack), you can put these in there with more food and even gel hand warmers. They will heat everything in the cooler up, and the cooler acts kind of like an oven, keeping the heat inside. We place one on each opposite end of the cooler (2 of them) and they heat from both sides. More bang for your buck.

For the price. They work good. I use them with the pre made dinners from the self. I don't get super hot. It dose keep me from having a cold meal.

Never even worked. Not one of em.

A must have for emergencies and camping