Being a bit of a sweaty git after a commute a few months ago I decided to buy a Halo headband. For one reason or another I have only just started to wear it on my commute to work and I wished I had started much sooner. It does it's main job of keeping sweat out of my eyes, not a very nice experience but it also seems to keep me cooler and sweat much less. I have been arriving at work after 90 minutes on the bike feeling very fresh and most importantly virtually dry. I can only speculate that the headband is retaining sweat to keep my head cooler thus meaning less need to sweat. It also seems to result in being less thirsty as well.