It works as well as expected. I install home security and this is a major help in attics. It won't keep you comfortable in 150° attics, but it will help prevent heat related illnesses.I wear it under my shirt to prevent it from snagging on nails or getting covered in dust and insulation.I understand that this isn't the ideal way to wear it and that may hinder my experience.Overall, I'm happy with the product and have recommended it to my entire team.The worst product I purchased this year. I got it as a present for a friend in Israel. He wears it twice. The first time was ok the second time all the gel went out and he can’t use it anymore.Cooling packs were like little silica gel packets. I was expecting more like ice packs. I felt the price was too high for the quality so I returned it.I like the cooling effect but it don't cover enough area to effectively cool my coreI keep it in the freezer in between waxed papers , it will last at least 5-6 hours . It worked for me . After trying many different ones.Disappointed with sizing. Read reviews and tried to act accordingly. I agree! The sizing is way off!NoneI ordered this '2COOL Gear Cooling Vest' in Medium. The sizing in the listing was terribly confusing and it remains confusing even after receiving and rereading the product listing.Sizing:I ordered 'medium'The vest that I received is tagged/labeled 'L-XL'But it fits like a men's small or even smaller than a men's small.So I needed my petite daughter's help to actually test this vest out fully. She is just over 5' and thin/petite. It was actually a little too small for her in length and also lower body width. She estimates it to be close to the size of a youth XL and maybe that is why it is tagged 'L-XL'.Usage steps/process:There is quite a bit of effort involved to use and maintain this vest. The vest cells are filled with a powder that when soaked for an extended period becomes a gel. After a few hours of soaking, the cells were still absorbing so we left it soaking overnight. Next you need to remove it from water and roll it out in a towel to absorb the surface excess moisture. So at this point it is damp (but not surface wet) and you have the option to use it at room temp or cool it in the fridge.For the first test we tried it out at room temp.Wearing it contacting the skin is tolerable but I would not say it is comfortable. So we opted to wear it over a shirt.As far as cooling goes, the moisture in the gel provides a cooling while it is dehydrating and displacing heat from your body. It is converting itself back from a gel into a powder as it absorbs heat from your body. This cooling is not overly-dramatic but it does absolutely cool you consistently. After several hours of use the cooling effect still existed as there was still moisture in the vest and even the next morning it was still 'cooling' when put back on.Next we rehydrated it and cooled it in the fridge for ~2 hours and as expected it was much colder when wearing. The additional coldness lasted ~1 hour and then it resumed its normal cooling feeling.Appearance:well... I do not think it is attractive largely because of the color. I would prefer maybe black, white, blue - or anything that does not make you look like a bandage.My opinion after testing is that this vest may be ideal for athletes where refrigerated cooling is both too cold andtoo short in duration. Perhaps this vest would be ideal for extreme athletes as it does absolutely continue to cool for a very long time without refrigeration and simply at room temp. There is a decent amount of effort to get this vest ready for use (soaking for many hours, rolling moisture out, and it does take days to dry on its own).Unless you need extreme use, I do not think this is a practical choice and would favor something simpler like gel-packs in inner vest pockets. Those would only last an hour or two but without all the overhead of prepping and also considering what you do at the end of the day to either dry this vest out or get it ready for the next day.I debated between 2 or 3 stars and only went with 3 stars as this MAY be an excellent choice for the right user but I do not feel it is the right fit for a casual user looking for a cooling vest and little details are provided in the listing to allow decision making.