Hi-Tech Cooling Undershirts

Even though it’s winter, I’m going to switch gears for a second and talk about undershirts designed to keep you cool.

As you’ve likely seen, I’ve written about cooling apparel before, including about other cooling shirts.

The common theme with those other shirts is that they have to be worn by themselves as outer cooling shirts for them to be effective.

The list below expands on that concept, allowing the wearer to sport these hi-tech cooling shirts as their under/base layer.

Since primarily used in sports scenarios where individuals can easily overheat, most of shirts in the list below use some sort of cooling mechanism.

You’ll see what I mean below.

Be sure to check out my Top 4 Cooling Apparel Categories article if you’d like to learn about what cooling technologies are available. 

If you’re looking for cool, lightweight daily-wear undershirts, check out my Thin Cool Undershirts article. 

Cooling Undershirts

Here’s the email the triggered all the research and discovery:

I am looking for something like this Ultra Cool RVU Undershirt.

Basically we are looking for a way to keep the drivers cool during the race.

I also saw this website called cooling shirts and their products would be great. But, I think is gonna cost too much.

Our budget is about 230 euros for each suit.

If you know something more about it please contact me!  

Thank you Tug!

Cooling Shirts / Cooling Undershirts / Cooling Vests

My Response:

The RVU undershirt is no longer being made, however, I do have contact information for the inventor who could let me know if she has any remaining inventory.

Though, the RVU does not have any actual cooling channels that allow a coolant-like substance (i.e. cold water) to be sent through the shirt.

The RVU is actually made from a Coolmax moisture wicking mesh fabric and uses the baffles in the shirt to keep the outer/over shirt from coming directly in contact with the full torso.

By allowing for that gap between the undershirt shirt and over shirt, it creates air channels that aid in sweat dispersion/evaporation — keeping the wearer cooler.

i suppose if you determined that the RVU undershirt really worked for your purpose, and you couldn’t get any more of them, we could find you a manufacturer or a seamstress that could make something similar for you.

In addition to the RVU, there are some other potential options:

CoolShield Vented T-Shirt

Very similar to the RVU undershirt, but with fewer channels.

CoolShield vented cooling t-shirt

Learn more: CoolShield Kevlar Undershirt

TECHKEWL Cooling Vest

Phase Change Cooling Vest. Maintains 58 degree cooling temperature for 2-3 hours.

TechKewl phase change cooling vest

Learn more: Amazon

FlexiFreeze Ice Vest

Uses 96 pure water ice cubes to lower core temperature. Good for indoor/outdoor use.

Ice cooling vest

Learn more: Amazon

Veskimo Micro Climate Cooling Vest

No longer being offered by the company, however, you may be able to find some used ones on eBay.

Veskimo personal cooling vest

Learn more: veskimo.com

Ultra Chiller

Similar to Veskimo and CoolShirt.

Ultra Chiller Cooling Vest

Might be a little more expensive with having to buy the cooler separately.

Learn more: ultrachiller.com

Arctic Heat Cooling Vests

Similar to the Ice Tee, but higher priced at nearly $200/per.  

Made with body-cooling materials – Sportwool, Microfibre and pockets of gel which are designed to hold any temperature for extended periods.

Learn more: arcticheatusa.com

Steele Vest

Usies cold gel packs to keep you cool.

Learn more: steelevest.com

Kool Max Cooling Vest

From Polar Products – gel pack based. full vests are around $120, but they have some partial vests for under $100.

Learn more: polarproducts.com

Sports Cooling Vests

From Glacier Tek. Prices start at around $189

Learn more: glaciertek.com

Columbia Omni Freeze Zero

The makers of the Omni Freeze Zero state that their technology can cool the wearer down up to 10 degrees. Though, I don’t think it works as effectively if worn as a base layer underneath a bunch of other gear. I think it has to be worn on its own.

Learn more: Omni Freeze Zero | columbia.com


This cooling shirt uses Polyvinyl Alcohol disks, a state-of-the-art synthetic material, that absorb water. When air passes over the disks, it creates a cooling effect.

From my experience with the product, I think it also has to worn alone, and not as an undershirt.

Learn more: No longer available

Past articles: FROS-T Cooling Shirts | FROS-T Seeking Investors

The Ice Tee

Moisture wicking athletic shirt that uses frozen gel packs and integrated products to keep the wearer cool.

Price: $74.95 per shirt with 5 gel packs.

The Ice Tee Cooling Shirt

Learn more: No longer available (Original links: theicetee.com | coolingshirts.co

Hybrid Ultra Sport Cooling Vest

Soak in cold water before wearing, also has cooling inserts that can submerged in ice cold water.

Learn more: No longer available (Original link: northamericanpride.com)

Rite Temp Athletics Cooling Vest

Looks like they use a special HTFX technology. Prices start at around $139.

They have “endurance” and “performance” vest types so you can choose high-cooling, shorter time, or moderate cooling longer time options.

Rite Temp Athletics Cooling Vest
Rite Temp Athletics Cooling Vest

Learn more: No longer available

Have You Tried Any Cooling Shirts or Cooling Vests like the ones listed above?

If so, tell me about them in the comments section below.

14 thoughts on “Hi-Tech Cooling Undershirts”

  1. I work inside with very little ventilation and it gets extremely hot and humid here in North Carolina.

    There are fans everywhere but they just circulate hot air. When it is 90 outside it is 120+ in the building and I am having a hard time finding something to fit my budget that will help cool me down.

    I am not lucky enough to have $200 to blow on something that might not work so I have been looking for something in the $50 and below area and nothing I have tried has helped.

    We also have to wear long pants shorts are not allowed and I’ve been having a hard time dealing with this heat.

    Do you have any suggestions of products I can try?

    • heya shawn! good to hear from you buddy and thanks for posting your question!

      so i don’t recommend anything you may have already tried to stay cool, can you tell me what products/options you’ve tested so far?

      also, can you tell me if you have any restrictions — like whether or not the product can be visible, if you have access to a refrigerator, are you open to wearing something over (or under) your existing clothing, and what type of clothing/shirt you currently wear.

      do you care more about staying cool, or not working in sweat-soaked clothing that gets weighed down?

      that should help me narrow down the list of recommendations (:

      • There is a cooler nearby that is accessible on breaks, every 3 hours or so.

        I have tried the Frigga toggs towels, didn’t work well. I’ve tried the old navy active t shirts which have worked the best so far but are still not that great.

        I’ve tried starter active dri t shirts from Walmart and they sucked.

        That’s all I have tried shirt wise. As far as pants I’ve tried lightweight twill not too good in humidity.

        The best I have found so far are Russel athletic pants with dri360 they are thin and seem to wick fairly well but are still hot. The only restriction work has on shirts is they must be tucked in and sleeves must be at least 4 inches in length.

        I don’t mind if the solution is visible as I’m not there for a fashion contest.

        Thank you for your time. I hope I answered all of the questions to your satisfaction. I really appreciate any input you could give me. This heat is killing me!

      • heya shawn, sorry for the delayed response.

        i’ll be writing an article this weekend about this topic a bit more.

        the truth is that unless there is a catalyst (air flow, phase change, ice, liquid cooling), there isn’t a full-proof solution.

        granted, “cooling” undershirts / shirts, or performance undershirts / shirts will likely perform better than regular ones, but the difference may not be notable enough for it to be the solution you’re hoping for.

        stay tuned for my article this weekend. it’ll touch on a product in this article, as well as one other.

  2. I’ve been looking for a cooling vest you can wear underneath military OTV interceptor body armor.

    I have to lug around 145 pounds in 110 degree heat with no body moisture evaporation due to high humidity. 68% or more.

    I’ve had heatstroke 4 times this year alone and need to find a vest that actually has an electric cooling system. Maybe with veins of liquid connected to a battery pack that freezes the veins.

    With all of this gear on. Plus 7lbs of helmet on my head. There is no place for heat evaporation while sprinting under the summer heat.

  3. Under Armour Iso-chill or Columbia Omni-Freeze Zero or ??

    Anything over 68 degrees with mild activity I start overheating and dripping. I live in Oregon’s Willamette valley summer average 80 degrees at 50% humidity.

    • heya craig, good to hear from you buddy and thanks for your question!

      are you looking for something to wear as an undershirt? or are you looking for an athletic gym shirt?

      • Looking for an every day out and about tee shirt i.e. mowing the lawn or a trip to the store or an hour at the gym.

        Thank you

      • gotcha. i think that both the iso-chill and omni-freeze zero would be worth checking out. seems like both brands offer a nice selection of items using those technologies.

        there’s not much info about iso-chill, other than it has ubf protection. they have different fabric blends, so either the iso-chill is using something like an xylitol additive for the cooling effect, or they’re applying something else.

        there’s a bit more information about omni-freeze zero, but whether or not it’ll perform better, is probably a bit subjective.

        sorry i can’t be more help. i don’t have any direct experience with iso-chill and i don’t find myself in situations where i need gear like this in an outdoor setting.

        for what it’s worth, these technologies need airflow and sweat to “activate” the cooling (evaporative) effect. so the best way to wear these shirts is by themselves, with nothing over and nothing under them.

        if there is no airflow, like while working out at the gym, you may not experience the full or any cooling effect.

  4. I’ve used the CoolVest and the RVU.

    CoolVest was just plain too thick. It probably promotes cooling from the outside BUT it doesn’t allow sweat to go anywhere very easily.

    I hike in the Arizona desert. When your body creates heat internally, it tries to get rid of it by sweating and causing the “evap-cooler” effect on your skin.

    Applying a thick, wet blanket (CoolVest) doesn’t promote that evap effect very well.

    I wore the RVU under a ballistic vest as an LEO in hot and humid Arkansas.

    It’s still hot and humid under there even with the RVU on.

    But a lot of us would rig up some kind of air hose/funnel gizmo so that we could actively pump cold AC air from the patrol car and force that air under the vest.

    The RVU allowed that cold air conditioned air to flow well.

    Here in Arizona, I actually find that a plain old all cotton T-shirt works very well in the scortching heat.

    Body sweats, T-shirt gets wet, breezes create the evap-cooler effect on the SHIRT.

    That cools the body under the shirt.

    – Sarge

    • hey sgt lumpy! thanks for stopping by my site and posting your comments!

      that “hose/funnel gizmo” you’re referring to is called cool cop.

      officer ron is the guy who invented it and it’s been available for a long while. if you take a look at his website, you’ll see that he’s working on a bunch of new cool stuff too! very neat.

      as it pertains to wearing an undershirt under a ballistic vest, i think the common complaint about cotton is that it can get feeling damp, takes a long time to dry, and can get smelly.

      though i’ve heard that since the shirt soaked up most of the sweat, the kevlar carrier wouldn’t get as nasty as when wearing moisture wicking gear (polyester, nylon, etc.).

      also, generally speaking moisture wicking undershirts (aka: under armour-like) would stink up a lot faster then cotton.

      though in a more traditional setting, i think a lightweight, not fitted cotton t-shirt would be great too.

      that said, there are plenty of lightweight, breathable, synthetic undershirts that wear very cool as well.

      the key question is what will be the wearing application? meaning, will you be wearing the undershirt/t-shirt alone, or will you be wearing it underneath another garment.

      and, what will you be doing?

      these hi-tech cooling undershirts listed in this article are really designed to be worn in more strenuous activities, like running, high-end training, motor sports, construction/roadwork, etc.

      lastly, i’m really keen on your point of how air flow around a wet t-shirt creates a big cooling effect.

      i can tell you that i experience that coolness very regularly after working out when i’m leaving the gym and walking to my car or home.

      my base layer shirt is usually soaked and the cool air passing around my torso really makes me cool/cold!

      off hand i don’t recall if i feel colder when my base layer is cotton or when it’s polyester or nylon, but needless to say, i can get cold really fast in that circumstance!

      thanks again for stopping by and posting your comments!


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