Before you deal with these wasps, have some tobacco handy, (a cigarette, cigar, chewing tobacco or snuff). If you get stung again, wet the tobacco, (for example, break open the cigarette, moisten the tobacco with spit, working the spit into the tobacco with your fingers) and slap it on the spot that got stung. Hold it there for 20 to 30 minutes, (you can tie it on with a rag or even put a bandaid over the tobacco to hold in it place - the longer it sits there the better). The wet tobacco will draw the poison out of the sting and it's won't be sore or swell. My Uncle showed me this when I was little and I've done it ever since - works every time. You'll know it's drawing the poison when you feel it slightly burning at the spot of the sting. The quicker you can do this, the better.