I got stung by YJ's 14 times last year while checking a trail cam up next to a creek. I literally ran out of my shoes trying to outrun them down the creek bed. I was over 100yds away bf I could stand still without being attacked. Meanwhile, my son and brother sat in the truck about 40yds away and just out of sight of the camera, unaware of what was going on. After about 10 minutes I heard the truck shut off and the doors slam. I started yelling, telling them not to go toward the camera. They walked down the road and helped me pick a route through the briars to the road. I'm allergic to nothing, but nausea set in about 15 minutes later and I was in pain for several hours. A double dose of Benadryl and a two hour nap, and I was good to go. YJ punch way above their weight.
I got my revenge the next morning. I sneaked up and poured a cup of gas in the entrance to the nest. When I checked the camera several days later, there was an armadillo and then a racoon tearing the nest out of the ground. SWEEET!!!
Several years ago while mowing shooting lanes in shorts and a tee shirt, I brushed up against a hornet nest. They didn't sting me, and I didn't know they were there. On the return pass, and a few feet to the side, I got got!!! I slapped the tractor into neutral and bailed off. I only had two stings, but one left a BB sized knot on my thigh that is still there. I now use a bee keepers shirt and hat, and wear gloves and long pants and boots.