My dad had a survey crew member killed by hornets in the early 60's. He stuck a bateau pole into a hornet's nest, in a tree overhanging the creek he was on, that fell into the bateau. He was dead before they could get to him, from over 100 stings. These big insects can sting repeatedly, not die after a single sting like a bee. One time for me and as you said it throbbed for hours as if the muscle was bruised from the toxin. We have far more yellow jackets in our part of the state but we had a huge hornet's nest on our house in 2008. Got the pest spray guy to juice it and melt the nest, killing all the hornets. Not something to play around with.

Bill