Emergency Zone ReDo Reusable Long Lasting Pocket-Sized Hand Warmers. Non-Toxic. Great for Cold Weather, Heat Therapy, Joint, Back, and Muscle Pain, Cramps, Arthritis.

Edit: 8/26/2015Amazon sent a replacement package, which wouldn't activate either, no matter how much I clicked the little discs. After fiddling around with them, they all eventually worked. What I found was that the little metal disc is easiest to "click" when it is around the edges of the gel pack, BUT clicking there often doesn't activate the process. Working the disc into a "deeper" part of the gel pack, then clicking, seems to work every time (so far) on all four of my warmers. This should be noted on the instructions.-------------------------------------------------------------------One worked, one didn't. The one that works gives about 25 minutes of good warmth.

They work and they are reusable, and reasonably priced. They don't provide a lot of total heat. I recommend using them in a hunter's muff, not just in a pocket. When I work in very cold weather, with steel tools and equipment, my hands get really cold and painful even with good gloves. When I take a break, I put my hands in the muff, take off the gloves, and activate one of these, then knead it for 3-5 minutes, and my hands are ready for another hour of work.

These work just fine. They get hot (not super hot) and stay that way for a good 30 minutes. I purchased these to battle eye fatigue. I am in front of a computer 10 plus hours per day, and I often get headaches and twitching eyelids from eye strain. These work great. I previously purchased larger click hot packs from click it hot packs (dot) com. Those have a better, stronger exterior shell, and they seem to stay hotter longer. But these Emergency Zone packs are great for small uses. I would suggest boiling them with a towel in the bottom of the pot since they seem to really stick to the pot, and they stick to each other if you are boiling more than one at once. Last night, I had to pluck a clumped up pair out of the boiling water and carefully pull them apart because they stuck together. I would suggest boiling one at a time if you don't want to constantly stir the pot.

Seller was fine--quick delivery. Product was disappointing. My expectations were that these would be pretty warm. I made flannel covers and thought that they would be nice tucked into a coat pocket for keeping my hands warm while I walk my dog. The packs got warm--warmer than tepid, but not as warm as a mug of coffee. The heat was barely enough to heat the flannel around the pack so I tucked my fingers into the cover and directly on the warmer. Not the warming I hoped for and the peak warmth only lasted for maybe 10 minutes. So--meh. Not cold, not HOT, and not just right for me.Second use: After boiling packs, the second use seemed a bit bettee than the first time. Packs got hotter. I also kneaded them this time as they warmed. Still warm to touch after 20 minutes, but not very warming to my hand.

My husband always has FREEZING hands in the winter, and I was tired of him freezing me out in order to warm them. Despite his protests, I told him I was going to buy him some hand warmers. After a bit of looking around I decided to try these, given their reasonable prices and the fact that they didn't need any fuel to stay warm. I had read some reviews saying that the metal disk was hard to click in order to activate the crystals, but when ours arrived they clicked right away and the whole pack heated up very quickly! A few days and a few uses later, and they are still just as easy to use.They seem to hold their heat very well without being in a glove for 30-45 minutes, more than enough for what we are using them for. It does take pretty close to 20 minutes of boiling to "reset" the crystals, but that hasn't been an inconvenience in any way for us so far.

I keep buying these so I should review them too. They seem to be the best deal around on sodium acetate hand warmers, and believe me, I've looked.Compared to other brands of hand warmers which are thin plastic pouches, the rubber enclosure for these slows down heat conductivity just a bit, making them not too hot to put on bare skin even right after activating, and also making them last a bit longer each use. This could potentially be a downside if you need maximum heat right away, but for hand warming use it's great.On top of being cheaper and made of a nicer material, this brand's warmers come with printed instructions and ingredients, which are not really needed once you learn how they work, but it's a nice touch and good for showing them off to friends.One caveat: the very first time you activate the hand warmers might be quite difficult. Be patient and keep flexing the metal chip. If it's too cumbersome, freeze them in your freezer and then thaw them out again in boiling water. After the very first use, they become quite easy to activate.

So, these do exactly what they advertise, and radiate heat for a very short period of time,bit do so effectively. My biggest complaint with them though is that they sometimes activate with the slightest touch, which is the exact opposite of what you want them to do when you're on a long trip and only want to use them at a specific period of time. You don't buy a lamp that turns on and off at the least opportune moments( imagine a 100 watt 3 am wake up call),not should you buy a hand warmer that works at the least opportune times...

Unable to snap the disk to activate; much too strong, can't flex. Able to active with two small sets of pliers.