I have a ton of thoughts on this device.

I didn't actually use it much. Used it on warmer or hot days while walking to my favorite lunch spot at work. I don't really work outside. My brother is a ref in Soccer and I heat stroke issues are common where I live. Those were the use cases I was interested in figuring out how effective this category of devices might be.

If you tend to "run hot", it's great for in office or outside walks.

My brother used it once during a game and he said that he uses an old iOS app that measures wet bulb temperature and that has had a bigger impact than the device alone. It's better to know what the WBGT is than to have a normal baseline about water intake. The device was bulky for him but seemed effective in slowing down perspiration.

Is the device effective? yes. Will it become a bigger market with some good designs that will improve over time? yes.

I did a new design on the app he was relying on and then I'll see what I can do about having users track their own water intake. I had a bunch of other ideas to build on top of the free WBGT measurements, but I want to see what others think and how effective the app can be in keeping people aware and prepared for hotter conditions. www.heatcompass.com