It's the heat + humidity that's killer. It's not possible to drink enough water to keep up with it, stuff with electrolytes is a little better but some days still not enough. I've heard people from hotter, but dryer, climates say that they have problems with the heat around here.

What's funny is when the worst of it passes and we start talking about how cool it is--when only a few weeks before, the same conditions were intolerably hot! This heat wave is supposed to break this weekend. I don't think it'll get this bad again this year. It might get hot again but it shouldn't be so humid.

My helmet is vented. But that breeze right on my head makes an incredible difference. My commute is only 2 miles each way, and I'm a trained & experienced cyclist.

Yehuda Moon refuses to wear a helmet at all!