If the victim has no allergies or signs of any allergy, it is now time to treat the sting and make it less painful. You will first want to wash the area gently with soap and water, if available. If you are not near soap and water, see if someone has a first aid kit. If so you can use an alcohol swab to sterilize the sting area.
You now will want to add cold compresses to the area to reduce the swelling. Either a washcloth run under cold water, or a baggie full of ice will work for a compress. I also like to elevate the area slightly if possible. My daughter has a tendency to play outside with no shoes, and has been stung several times this summer on the bottom of her foot. I will have her lay on the couch and elevate her foot with several pillows and apply a compress of a baggie full of ice, wrapped in a towel or wash cloth.
I also recommend giving the victim a pain reliever, and I also keep Benedryl on hand. There are also some home remedies that will help take the “sting” out of the sting. Such as, making a paste of baking soda and water, then apply this to the welt. I have heard of people using toothpaste, meat tenderizers and raw onion slices on the sting.