An allergic reaction to the sting of insects known as hymenoptera, that is bees, bumble bees, fire ants, hornets, wasps, yellow jackets, which unless immediately treated may be occasionally fatal. Seek medical help immediately.
Drink fruit and vegetable juices rich in vitamin C.
Ascorbic acid in ascorbate form in large doses.
Various essential oils such as citronella and eucalyptus applied topically, may act as repellents.