People with minor or moderate reactions to wasp stings should use a cold compress or ice to reduce the swelling at the site of the sting, states Mayo Clinic. Wash the site with soap and water prior to placing the cold compress.
A person stung by a wasp should first remove the stinger from the skin to prevent the spread of venom. Using a pair of tweezers is an effective way to do this, claims Mayo Clinic. Individuals can then proceed to clean the area of the sting with soap and water. If the site of the sting swells, the application of a cold compress to the skin can soothe the area and reduce pain.