If you have been in contact with poison ivy, Sachs warns not to wash with hot water, as the water will open up your pores and give the urushiol a more direct route into your skin. Even worse, using soap will emulsify the poison ivy oil, making it more difficult to get off. The best-case scenario for getting rid of the oil is to jump into a chlorinated pool. The chlorine will kill the oil. If there isnt a pool nearby, use a garden hose on a high-pressure setting to neutralize the oil.
While it's ideal to wash your skin within the first 30 minutes after contact, most people do not know they have been in contact with the irritant until 12 or 24 hours later when the itching starts.
(Text by Chris Brook / Boston.com Correspondent / Photo courtesy of www.poison-ivy.org)