• SAME DAY SHIPPING

    Need cooling fast? Orders placed before 1pm EST ship out same day!

  • 60 DAY EXCHANGE/RETURN

  • MADE IN THE USA

  • AWESOME CUSTOMER SERVICE

Stay cool, comfortable, and in control, empowering you to live life to the fullest by helping to...

  • reduce fatigue
  • beat cog fog
  • enable exercise
  • explore the world

Ruth’s Cooling Choice:

UnderCool 3 w/two sets of ExtendedCool Cooling Packs

Don’t Just Survive the Heat


  • Stay Cool Anywhere

    Works great in humid and dry climates

  • Cooling That Lasts

    Cooling packs last 1-4 hours depending on product

  • Stay Energized

    Lightweight cooling power that won’t drag you down

  • Feel Great

    4-way stretch comfortably fits all bodies and moves freely with you

  • Stay in the Game

    Ultrafast recharge times and 1000 reuse’s mean you’ll always have cooling

These are not AI Generated People. They are Real Customers!


  • With the ThermApparel Cooling Vest I was able to hike ten miles and summit my 14er.

    I have always wanted to climb a 14er and wanted it to be Mt. Sneffels. I have had issues with heat and being very fatigued on regular hikes. But with the ThermApparel Cooling Vest I was able to hike ten miles and summit my 14er. I changed my packs at the top, a total of 8 hours they kept me cool enough to achieve my dream while living with MS. Thank you!”

  • Lowered my core temp by a FULL 3 degrees.

  • I use mine for everything from taking the dogs out to performing on stage to running a 5k.

  • I love this product. It's paid for itself already in the safety and security I feel

    I do not have to stay at home sheltering in place. I can care for my grandbaby, run errands and, bike! Bicycling is my preferred exercise because of my MS gait & balance problems that make walking very tiring. I love this product. It's paid for itself already in the safety and security I feel when I take it with me during hot weather.

  • Using the Cooling Vest in wheelchair Rugby kept my post-game temps safe at 98-99°F

    I can not sweat due to my C7/T1 spinal injury and it affects my sports performance. Using the Cooling Vest in wheelchair Rugby kept my post-game temps safe at 98-99°F, enhancing my focus without constant cooling.

  • I traveled to the Jordan deserts, and had great relief from 100F temps.

    It enables me to do the things I want to do, w/o people knowing that I have it on. I traveled to the Jordan deserts, and had great relief from 100F temps.

  • I use it when I garden and also at the gym.

    I use it when I garden and also at the gym. I'm a fitness instructor and it makes it easier to teach. It has made it so that I can do hard things longer

  • I use it when I play tennis. Couldn't do without it in the heat.

  • My ThermApparel Cooling Vest will always be part of my Santa Outfit, summer and winter.

    I never have to worry about overheating again. It’s invisible under my vest and Santa Coat. It keeps me cool during home visits sitting near the fireplace or in the hot sun at the Christmas in July events. My ThermApparel Cooling Vest will always be part of my Santa Outfit, summer and winter.

  • I am able to battle the hot summer days doing what I love

    I have MS but it doesn’t have me. Thanks to my ThermApparel cool vest, I am also able to battle the hot summer days with my boy, doing what I love, rein, cowhorse and cutting!!!

  • Kayaking in the sun can be hot, so I wore my Cooling Vest.

    Kayaking in the sun can be hot, so I wore my Cooling Vest. It really helped out and after 2 hours when the sun was fading, I realized they were making me almost too cool, so I had to take them off!

  • The vest is really lightweight and I forgot I had it on.

    The vest is awesome, ten minutes into a regular fursuit photoshoot I'd be sweating, but we took photos for 2 hours and I didnt break a sweat.

Easy To Use

Cool It
Place in the fridge, freezer or ice water

Wear It
Insert cooling packs into the pockets

And Go
Anywhere you want, doing anything you want

SHOP VESTS

As seen on ActiveMSers.com

TOP PERFORMER: ThermApparel UnderCool

One frustrating fact of cooling vests is that they tend to be bulky, clunky, heavy, and most announce their presence like a 6-pound cyst growing out of your neck. ThermApparel is flipping the script and has designed a vest that is virtually completely hidden, weighs less than two pounds, and lasts longer than many of their larger, full-vest competitors. The UnderCool is ultra lightweight and stretchy, think sheer (and comfy) yoga pants, and comes in a range of sizes and two colors (back or white), cinching at the abdomen with Velcro. Perfect for sports, especially those that involve running. Cooling comes from four phase change (PCM) cooling packs that are inserted into the back of the garment—there is no cooling on the chest. We expected this to be a noticeable negative, but in our testing we still felt refreshed. And a huge side benefit of no cooling packs on the chest: there are no cooling packs on the chest so women (and men) of all chest sizes can wear this comfortably and stealthily. Expect the slim version to last 1-2 hours outdoors on a hot day, 2+ hours when worn indoors. The extended cooling packs add up to an extra hour of cooling power, and is a recommended upgrade.

Weight: SlimCool Packs - 1.3 lbs, ExtendedCool Packs - 1.9 lbs

Why We're Better


  • Evaporative Cooling

    • Doesn't work in humidity
    • Cools your skin, NOT your core directly
    • Lightweight & Flexible
    • Must be wet
  • Our PCM Cooling System

    • Works in any climate
    • Cools your core body temp
    • Lightweight & flexible
    • Dry conformal cooling
  • Gel & Ice Cooling

    • Works in any climate
    • Too cold for direct skin contact
    • Heavy & rigid
    • Wet from condensation
  • Don’t Just Survive the Heat
  • Thrive In It!
  • Don’t Just Survive the Heat
  • Thrive In It!
  • Don’t Just Survive the Heat
  • Thrive In It!
  • Don’t Just Survive the Heat
  • Thrive In It!