MISSION Cooling Helmet Liner - Lightweight & Breathable - Cools Up to 2 Hours - UPF 50 Sun Protection - Machine Washable

It works and it works a bit better if you get it wet and keep it wet. It cools through evaporation, obviously. My head doesn't sweat as much as it used to which leads to it getting overly hot. This does help some.My only problem with this is the fit is a bit tight.

Had an issue with sweat running in my eyes while playing ice hockey and blurring my vision to the point I couldn't see the puck clearly. I felt like a ref. This keeps the sweat away and now I can't use that as an excuse for heeling every pass to the other team. I did have to slightly adjust my bucket to accommodate it, but that is a expected.Would recommend for ice hockey players!

(edit: New Update added at the end Nov. 2024)Me: mostly bald road & MTB cyclist who sweats a lot from the head. I give you this background and the next paragraph to help people like me who read through great reviews of a product and purchase it based on those reviews only to find it doesn't work well for me.I've tried all sorts of sweat management equipment to keep sweat out of my eyes and off the inside of my glasses while I'm riding. The Sweat Guttr does OK but interferes with my helmet. The Halo headband quickly saturates and then starts dripping into my glasses. Skull caps trap the heat in and make my helmet feel like a furnace and I usually end up taking them off.Despite my previous bad experiences with skull caps, I decided to give this Mission model a try based on their marketing claims. As the review title suggests, this product definitely outperformed every skull cap I've tried previously. It wasn't a miracle worker, however, and it did eventually allow sweat to drip.THE GOOD*It didn't feel hot. Heat wasn't trapped in like other skull caps I've tried. The evaporation kept my head at what felt like the temperature it would be if I wasn't wearing any covering. This also wasn't dependent on airflow, so it wasn't hot when riding slow in the woods on a MTB or fast on the road with lots of airflow.*Comfortable- fit well with all 3 of my helmets and didn't move around during the ride.*Kept sweat out of my eyes. My first ride with it went great. It was a lower humidity day and I took the road bike out for a 2+ hour ride at an easy pace. I started with the cap dry as it wasn't hot enough to need the cooling right out of the gate and my head would wet it quickly enough. I only had two drops of sweat fall into my glasses the entire ride. Even better, the cap pushed the front pad of the helmet where the sweat dripped from beyond the top of my glasses, so it landed on the outside rather than the inside like usual, so that was a win. The second ride was a hard hour in maybe 65% humidity and lower 70s temps. The helmet and liner saturated after 49 minutes and started dripping regularly (again on the outside of my glasses at least). Without the liner I estimate I would've reached this point after about 25 minutes. The next test was a medium effort for an hour and a half at 80% humidity and mid 70s temps. I hit saturation at 43 minutes and sweat continued to drip profusefully for the rest of the ride. I will note that the sweat was dripping from the saturated helmet pad in front, not from the skull cap. Maybe a different helmet design could improve this.THE BAD*Didn't do much for mountain biking. High humidity in the woods, low speeds, little wind and hard efforts made for a drip fest. I couldn't tell any difference between wearing this and wearing nothing. It probably delayed saturation a little, but not by much.CONCLUSIONThis performs well enough to become my go-to sweat management for warm weather rides. 4 stars overall. Mission will need to get its tech team busy designing a new super-material that can evaporate the sweat faster than I can produce it to create the perfect cap that earns 5 stars from me.Update Nov. 2024: For those who have the same sweat dripping problems as me, I suggest giving cycling caps a try. I got one and like it better than this skull cap for sweat management. The brim of the hat draws the sweat out to the front and lowest point when my head is down in a riding position and gets the sweat drips far enough out that it doesn't drip inside my glasses. At road speed, the sweat can still get blown back onto the outside of my glasses at times, but this is easier to wipe away than the inside, so I rate it as an improvement over every other sweat management system I have tried so far. Some caps are made of a similar material to this liner that breathes fairly well.

Fits great and works wonderfully.

Why did you pick this product vs others?:It fits well, protects my scalp from the sun, and is well constructed. It helps keep the sweat out of my eyes. I think that the white color keeps me cooler but than darker skull caps that I have worn.

I use the cap under my bike helmet. Quality is excellent and the fabric is also excellent. The cap in my opinion is a little pricey. It washed and drys well.

This thing is amazing. The cooling feature is great, and it fits snugly however you choose to angle it. Can put it in your pocket when not using it. Great for traveling, hiking, or just walking around outside on a hot day. Provides sun protection and cooling simultaneously. Would absolutely buy again.

Where underneath bike helmet during summer. Comfortable and helps keep head from getting sunburned