Is UnderCool a Cooling Vest?
When people ask us, "Is UnderCool a cooling vest?", the answer isn’t a simple yes or no — it’s more like: maybe, but it’s something better.
What Is UnderCool?
UnderCool is lightweight cooling gear designed to provide the comfort and temperature regulation of a cooling vest, but in a far more discreet, comfortable, and wearable form. Unlike traditional cooling vests, UnderCool is made to be worn under your clothes, thanks to its low-profile, flexible design using 4-way stretch spandex and mesh materials.
It uses PCM (Phase Change Material) cooling packs — a sophisticated, non-toxic, bio-based material that absorbs your body heat as it slowly melts, keeping you cool without the mess or risk of burns that can come with ice or gel-based vests. The PCM packs are also reusable and recharge easily, again and again.
At just 2 pounds including the cooling packs, UnderCool is perfect for people who deal with heat sensitivity due to multiple sclerosis, POTS, or other neurological conditions. The unisex design works for both men and women and fits snug like an undershirt or camisole, helping battle fatigue and allowing you to get back to enjoying life’s simple pleasures — like graduations, BBQs, or walks in the park.
So, Is It a Cooling Vest?
Yes, but it’s a major leap forward from the traditional, bulky vests you’ve heard of, which no one wants to wear. UnderCool 3 provides more core body cooling in a lighter, far more wearable package. It won’t make you look like you’re gearing up for a snow expedition in July. In fact, you can wear it invisibly under everyday clothing and stay cool while still looking sharp.
Want a more Traditional Cooling Vest? Meet UltraCool.
If you're looking for something more like traditional cooling vests—the kind with full-torso coverage and maximum cooling capacity—ThermApparel has you covered there, too.
Our UltraCool cooling vest is what we call a true cooling vest. It builds on the same smart design and comfort-focused features of UnderCool — like 4-way stretch materials and bio-based PCM packs — but doubles the number of cooling packs for more powerful, full-body cooling. The packs wrap around the torso, giving a traditional vest feel with modern tech and built-in comfort.
Drawing on the learning from UnderCool, UltraCool is also significantly more female-friendly than traditional cooling vests. The placement of the packs fits women's bodies just as well as men, something that can’t be said about most cooling vests.
Looking for Something Else?
ThermApparel offers a full range of cooling products. You’ve already heard about our more traditional Cooling Vest products, but there are lots of other ways to stay cool too:
RallyWrap:
provides the same long-lasting cooling of our vests in a versatile package that you can wrap over your shoulder, around your legs or waist, or even as a seat cooler.
Headband:
Provides up to 1 hour of cooling and can be worn as a traditional headband. Thanks to our patented Flex Cool cooling packs, it also works great around your neck.
CoolSleeves:
Provide up to 1 hour of cooling to your radial artery along your forearm. Weighing the same as a smartwatch, you will forget you are wearing them at all.
The Bottom Line
Whether you need everyday cooling support or powerful protection for extreme conditions, ThermApparel has a solution for you.
From our discreet and wearable UnderCool to the high-capacity UltraCool, plus flexible options like RallyWrap, CoolSleeves, and Headbands — you can build your own cooling toolkit.
With interchangeable PCM packs, modern materials, and science-backed design, we help you stay cool, stay confident, and live life without limits.
ThermApparel is a small business making big waves in the heat sensitivity world by designing the first lightweight, comfortable and invisible cooling vest, UnderCool. Check us out online, on our blog, or on Facebook, Twitter, Pinterest, LinkedIn and Instagram.
Please let us know if you have any other questions or ideas in the comments below, we will follow up. You can always reach us via:
Live Chat - www.thermapparel.com | Email - contact.us@thermapparel.com | Phone - 855-232-7233 | Address: ThermApparel LLC. 40 Franklin St. 4th Floor, Rochester, NY 14620