The recommended first aid is: wash the sting area with copious amounts of warm soapy water then wash the bite site with household ammonia, scrubbing vigorously with a sponge to get under the skin flap to the poison.
Make a solution of baking powder, meat tenderizer, and ammonia, i.e. 1 teaspoon baking powder, 1 teaspoon meat tenderizer, and 1 cup ammonia. Scrub this solution into the wound.
The ammonia and baking soda return the body's acid/base balance to normal neutralizing most of the effect of the poison injected into the skin by the insect. The meat tenderizer's enzymes help break down the protein aiding the solution in neutralizing the poison.
I keep a pint jar of the solution stored at room temperature. It's very effective.