By Muriel Bristol | May 15, 2018
The itching caused by bug bites, as well as that caused by poison ivy and poison oak, may be relieved by the brief application of hot water.
Run the affected part under the hot water tap, or soak it in a bath of hot water, or apply a washcloth soaked in hot water. It should be as hot as you can stand it, but for just a few moments (about 5-10 seconds or so). (The water should be 120 to 130 degrees in temperature, which should not be damaging during such a brief exposure. (120 degrees is the mandated upper limit for modern water heaters)).
Obviously, when you can no longer stand it, withdraw the body part. DO NOT SCALD YOURSELF. This should not be used for open irritated wounds or more chronic skin diseases.
This should provide localized itch relief for 2-3 hours, at which point it could be repeated, if necessary.
This method is a folk remedy of long standing. It appeared in print in the 1961 textbook Dermatology: Diagnosis & Treatment. It is thought to work because itch and pain receptors are intertwined. Overloading them with hot water blocks the itch.
See also Black Flies Return
Graedon, Joe. (2009, August 9). Hot Water for Itchy Bug Bites. Retrieved from https://www.peoplespharmacy.com/2009/08/01/hot-water-for-itchy-bug-bites/
Sulzberger, Dr. Marion B., et al. (1961). Dermatology: Diagnosis & Treatment. Chicago: Year Book Medical Publishers
Wolf, Lauren K. (2011). Itching to Know More about Itch. Retrieved from https://pubs.acs.org/cen/science/89/8927sci1.html