Basketball player dunks while wearing super lightweight UnderCool cooling vest.


No one wants a bulky cooling vest weighing them down. That's why UnderCool weighs less than 2lbs— including the cooling packs!

Woman practices yoga while wearing ultra-comfortable UnderCool cooling vest.


Made from breathable mesh and wicking fabrics, the UnderCool is designed to keep you cool and dry. Our flexibility is unmatched!

Mom wears invisible UnderCool cooling vest while at her daughter's soccer game.


Our slim design conforms to your shape, you can even wear it under your clothes. You can stay cool and no one else has to know!

A display of UnderCool cooling vest's key features, including adjustable straps, velcro fastening, breathable and wicking fabric, and it's all machine washable. The cooling packs are safe on skin, biodegradable, non-toxic, and FDA approved for cooling garments! The UnderCool cooling vest fits all sizes, can be worn under clothes, weighs less than 2 pounds, has 4 way stretch, and provides cooling relief for up to 2 hours!

3 easy bundles just for you! Pretty cool, huh?

"ThermApparel has flipped the script on cooling vests.
 UnderCool is a game changer."

  -Dave Bexfield, ActiveMSers

"UnderCool helps me keep up with my grandchildren."

"I have been living with MS for over 20 years and I've worked very keep to keep it from coming between me and my family. For years we avoided traveling in the summer because I couldn't handle the heat. I avoided other cooling vests because they were too big and bulky. The second I saw UnderCool I knew it was perfect for our next trip to Disney World! I was able to spend just as much time out in the sun as my grandkids, I love it!"

Basketball player smiling while wearing UnderCool cooling vest.

Join our cool family.

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