A Portsmouth NH start up: CoolCore is introducing fabrics which claim to cool your core as you exercise.
I have used a Craft T-shirt which makes some of the same claims and found it to be my day in day out go to shirt for our recent Chamonix to Zermatt trek. Call it a good micro climate but no discernable cooling effect.
I recently purchased a CoolCore bandana and put it to the test. The bandana was made of a felted material on one side and smooth fabric on the other much like a backpacker towel but more flexible. Wet with warm water, wring, snap. I was very surprised that within seconds the bandana which had been soaked in warm water turned distinctly cool to the touch. I wore it around my neck for several runs on warm days and it stayed cool and felt very pleasant. After "initiating" with the water heat, sweat and motion continue the cooling effect. As I run hot any cooling effect has for sure a psychological effect. Remains to be seen what physiological effect occurs. As suggested on the CoolCore blog I also soaked the bandana, put in freezer for 5 minutes and used to reduce swelling on my sore knee. Sore from the Swiss trek and then a hard downhill on Spiro in Park City.
Moving to shirts made of the material, I contacted CoolCore and they were kind enough to send me a golf shirt. It was size large so not as form fitting and close to the skin as a medium might be. The material felt much like my Craft T-shirt: a bit slick but fairly thin. Not a mesh for sure. I did not soak the shirt for my first test as Michael Simchik the CEO of CoolCore told me motion and sweat would activate the cooling effect. Temperature was a mild 70 F with relatively high humidity. After about 20 minutes of running, when the sweat got going, I definitely noticed a slight, almost tingly cool feeling on the skin where the fabric was wet. Further, testing in high temperatures are in order but CoolCore is a very promising to cooling. I tend to run hot and if core temperature can be reduced even a small amount, comfort and performance benefits should follow on a hot day. Not to speak that is it just more pleasant to be cooler!
How do they do it? From the CoolCore web site Technology page:
"The fabric is engineered with a unique variety of fibers that when structured in a designed way creates a series of high-density capillary network, where the water molecules are absorbed deep into the fabric core and hydraulically compressed into the voids within the fabric. This void within the fibers creates an orientation of the water molecules in such a way that when the product is activated (snapped) it allows for maximum evaporative cooling to take place from the vibration of the snapping. At the same time, because of the uniqueness of the combination of different fibers and their reaction to one another, the suppression of water loss by evaporation (high absorption and wicking simultaneously) suspends the water within the fibers for an extended period of time."
CoolCore says their fabrics' cooling effect is achieved without chemicals, phase change materials, or polymers. There appears to be some anti-microbial effect but at least for the golf shirt not as effective as the all time winner, wool.
CoolCore does have t-shirts, bandanas, sport towels, etc... for sale on their web site but their longer term plan is to license the fabrics and technologies to apparel brands.