Will hot water agitate a poison ivy / oak rash?

Hot water no help : Poison ivy is a contact dermatitis that takes 10 - 14 days to clear. Hot water will cause the superficial blood vessels in the skin to dialate making the area redder and if hot enough briefly numb nerve endings. It will not in anyway improve or shorten the natural course of poison ivy. The only treatment that partly helps is oral or injectable steroids, but side effects can be significant.