If the blisters break, cover loosely with a sterile bandage. I've never gotten the rash before. Yes, you can begin getting the rash at any time during your life. Three out of four people are sensitive to poison oak and ivy. Sensitivity is just a matter of being exposed enough times until the body becomes allergic to the poison oil.
Air is helpful to healing any wound.
If you cover the rash with a sterile bandage, cover lossely to allow healing oxygen to reach the surface of the skin. Seek medical attention if rash becomes red, feverish or shows other signs of infection. The poison oils remain toxic and do not evaporate. All parts of the living or dead poison plants, including the roots, contain the urushiol oils. Be especially careful of dead vines on firewood and leafless vines in the winter.