This time of year, even in upstate NY, sweat control is a real issue. I've taken to carrying 2-3 halo headbands and every 15-20 miles will stop and change them. Wring out the used one as best you can and hang it from the handlebars or elsewhere to dry, just in case you need it again. Its best if you can do this at a real road stop and run it through some fresh water, but no matter. Also, I travel with a terry washcloth tucked into the rear of my bike shorts. I'll pull that out while riding for a quick wipe off and while stopped for a major cleaning while changing headbands and wiping off glasses.