I know how that feels! But then you probably figured I've done that too! Takes several days to stop stinging, but it finally will. When I was like 18yrs old, I was working on my Honda CB450. Been running it sitting still, trying to get the valves set proper. Pipes were super hot. Lost my balance sitting on my toe tips, and naturally reached to grab something. Got my entire hand! Aloe plant juice helps.
I know the feeling. I was working under the dash of my buddys mustang last week, he had a 100 watt bulb in his drop light, it got me once on the forehead and twice on the arm. The marks last longer than the pain, I guess that's a good thing.