Not much of a story, I was guiding a dive on Davis Reef in the Keys on August 3, 1986. I found a Spotted Moray Eel and proceeded to show it to the group, they go gaga over morays. While watching the group out of my left eye and the eel out of my right, I gently brushed a Bristle worm with my left inner forearm near my elbow. It burned a tad worse than Fire coral. It wasn't really much of a big deal. Continue down the reef, farther and farther from the boat. While at the far end of the reef and pointing out nifty critters for folks to watch, I started feeling pain in my chest under my left arm. When I noticed that beginning, I started the group back toward the boat. Approximately half way back to the boat, the pain had moved to the center of my chest and I was having difficulty breathing. I obviously lived, but I'm not a fan of Bristle Worms.