Nope - cold water (or ice) on the area does NOT help. Only keeping the body/core temp down does...and that's not always easy to do.

FYI - I got these on my century on Aug 11th - it was cloudy all day and temps never topped 90 degrees. BUT, I did get hot/wilted near the end when I had no cold beverages left... I ended up with a slight break out. So, it's definitely not sun related.