The San Francisco air conditioning, aka cold sea breeze and fog that comes in the Golden Gate most afternoons, take care of that for me. I do get hot at the end of my ride, where its typically much warmer then SF, but its a short enough part of my ride I just deal with being hot and sweaty it helps that its a dry heat.

I have heard of a trick but don't know how well it works. Someone told me they wet a light base layer and put it in the freezer before wearing. Never tried it myself.