Sy Reene Don't forget that there are two types of sunblock, reflective, and transformative. The mineral-based (zinc oxide, titanium dioxide) sunscreens act to reflect UV radiation, while the chemical sunscreens (octinoxate, avobenzone, etc.) convert UV radiation to heat. I use both, but apparently the chemical sunscreens are better for sweating heavily (they absorb into the skin, under the sweat).
I was going to suggest the reflective to feel cooler, but it rarely stays put. I just ride early in the morning while the sun is still low.