This one time at band camp...yes, I know how it sounds.
They let the drummers take a little break while the rest of the band was working on formations for our percussion feature. We weren't needed because we were just standing still on the sidelines. We were in the woods off the edge of our practice field and I jumped into a yellow jackets nest. They were all over me and in my hoodie before I knew what was going on. 20+ on the face including 3 in my mouth. Couldn't count the ones on my arms and legs.
Fortunately I had no reaction other than the extreme pain.