Fuel leak at fuel bowls

Let me just mention that it was a hot July afternoon and had been driving mountains and then interstate for over three hours and then got stuck crawling in Friday traffic around Albany for a half hour or more. It was when I pulled off and was fueling up that I opened the hood to let things cool and saw the large pools of fuel in on the intake. :eek:
I tried loosening and retightening a couple times. but it wasn't until it cooled down enough - about a half hour later - that I could tighten it effectively. Not fun.
But it never leaked before or after. Of course I did replace them when I had a chance. The one pictured above wasn't going to seal much longer!