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

-Dave Bexfield, ActiveMSers

  • Unisex vest
  • Under 2 lb
  • Worn under clothes
  • PCM cooling packs
    • Do not get wet
    • Safe for skin
  • Cools for 2 hours
  • Under $200
Front and back view of UnderCool cooling vest.
  • Mens vest
  • Over 6 lb
  • Worn over clothes
  • Ice cooling packs
    • Get wet
    • Unsafe for skin
  • Cools for 30 min
  • $300 - $400

You've never cooled like this before!

Photo of woman doing yoga while wearing UnderCool cooling vest.


Made from breathable mesh and wicking fabrics, the UnderCool is designed to keep you cool and dry. Our flexibility is unmatched!
Photo of cooling packs being inserted into the 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!
Photo of cooling packs.


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!
Designed to fit every shape and size
Adjustable straps and velcro make a best fit every time.
Size Waist Length
Extra Small 24" - 28" 61 cm - 71 cm 15" 38 cm
Small 26" - 30" 66 cm - 76 cm 16" 41 cm
Medium 28" - 32" 71 cm - 81 cm 17" 43 cm
Large 32" - 38" 81 cm - 96 cm 19" 48 cm
Extra Large 40" - 45" 101 cm - 114 cm 19" 48 cm
What if I order the wrong size?
Don't worry, our awesome 30 day return and exchange policy has you covered.

Susan's Story

How UnderCool helped one grandmother
spend more time with her family

"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!"


Are you ready to Stay Cool and Be Cool?

Ships to the United States for under $19.99 and ships to the rest of the world for a flat rate of $45.99.