I had a trip overseas and I am a nursing mother. These were amazing I recommend 100% for traveling nursing moms they are TSA approved they dont turn to liquid so they will never be taken away. I had a 18.5 hour trip home. I used 4 bricks in my breastmilk cooler and only a few top bags ended up thawing out. But I think it was also because as I was traveling and pumping I put the warm milk on top. But even though they defrosted they were still ice cold and I came back with over 60 bags of frozen milk ranging from 2oz -4oz. I continue to use to keep milk cold while I work. I can not be happier. So far 3months later only one has been tossed because I accidentally knicked it with a fork while unloading my bag but they are durable and keep my milk cold for over 24hrs. As I once forgot to unload my bag after work and the next day the milk was still cold.

These blocks sure stay cold a long, long, long time. I work nights and use them to keep my lunch and dinner cold, and boy, do they!!

I use 3 in the cooler, then the other 3 stay in the freezer, swapping them around every day. Once they're frozen good and solid (that first 48 hour freeze they recommend) they stay cold a lonnnng time. Somewhere I read 4-5 days, but I haven't tried that length of time.

I just needed foods to stay very cold for about 12 hours so the food's safe to eat still. Ice wasn't working, those blue gel packs weren't cold enough, but THESE... ARE!!

Such a good price for 6 blocks. WAY easier than making ice every night and dealing with melting ice or using plastic bags to try and contain the runoff. These blocks do have some moisture runoff but it's normal and it's not from the heavy duty plastic they're packaged in; it's from condensation and it's not as much as what ice produced every night.

If you have a big cooler, sure use all of them, but for a small cooler, 3 works fantastically well, and keeps 3 in the freezer for the next time.

I flew from Jersey to FL using 5 of these, in two insulated bags in a checked suitcase, to keep homemade ice cream that I made to surprise someone frozen. When I arrived we had 7 hours of being out and about until our 3pm check-in. About 15 hours had passed when it was time to open it and one of the places we went let me put the bag in their freezer for an hour. I was scared to open the bag when it finally came time to reveal the surprise. It was a win! The ice-cream was still frozen!

I do think the double insulated bag inside a suitcase helped for sure. Also because these are foam I didn't have to worry about a ton of water melting but there is naturally a bit on condensation but far less than ice.

*IMPORTANT NOTE: Prior to purchasing these I noticed someone complained about how flimsy the bags were and that they tore. They are right! The plastic IS flimsy! So learning from their review I always keep each of them in their own closed ziplock back when I use them so I that the plastic always has a layer protecting it from tearing. WILL extend the life of these by a ton! I have never has to repurchase them. I even refreeze them in the ziplock. They basically live in their ziplock bags and from time to time I'll open them to clean them as needed.

Since the ice cream mission I have also used them wonderfully to keep my lunch, such as salads, cool on a summers day and to keep groceries cool when I am not heading straight home. Definitely happy I bought these.

I utilized this brix for medical purposes; it was the exact same product that my doctor uses

I used these to ship some stuff to our soldier in OK from NC and it took 2 days to get there. Everything was still nice and cool! We had one happy soldier to get some homemade goodies! Very durable, Last a long time and doesn't make things soggy or wet! My son started taking them fishing with him! I plan on getting more to keep me cool in the summer due to some heat intolerance issues I have, I'm sure they will work well!