I think there's a little stick of some kind of medicine or another you can buy to rub on a bite as well as not touch it, scratching makes it a lot worse. Other than that, try not to have a lot of sweat on you and don't stay still for a long time outside.
I use a hair dryer to blow on the bites until they don't itch anymore (can feel a bit painful when doing it), but it stops the itching for about 4 to 5 hours.
The reason for this is that the protein that causes the itching denatures at a lower temperature than skin burns.
So if you take anything hot, but not too hot, and hold it against the sting it will help with the itching. You get better results the sooner you do it after the bite though.