I always check for vines first. Without leaves, its hard to tell if the vine is poison ivy. Even in winter you can get the oil on your clothes. Once there, the oils can cause a reaction any time you use this garment unless the item is thoroughly washed.
Poison Ivy and Poison Oak are serious stuff. Either can cause systemic reactions, and even hinder breathing. If you've had a bad case , you are aware how maddening the itch, swelling and seeping of pus can be.
Sometimes you have to wade through a pathc of poison ivy. The Bartram Trail, near Wayah Bald is especially overgrown with it come June and July.
If you find yourself exposed to poison ivy or poison oak, wash in Cold water, never warm and absolutely never hot water, as soon as possible. Wash for several minutes, more is better. If you wash in a stream, do not use any soap; soap is not necessary. Hot water only spreads the oils.
If you are not certain of exposure, take the safe way out and wash everything. Change clothing if it has touched the plants, place items in a plastic bag and wash thoroughly in cold water.
Once all the oils have been removed, you can not transmit it to another person. Your body may react, but you are not contagious. Poison Ivy is an allergic reaction to plant material, not bacterias or viruses.
Some people recommend calamine lotion to relieve itching. I find the Polar Ice analgesic gel cools the area, and eliminates itching. You may find this works for you as well. Cold compresses help by reducing blood flow and keeping the inflammation localized. In my experience, warm compresses worsen the reaction by increasing blood flow. Scratching can break the skin and introduce infection. If you must, cover the area after applying cooling gel, to keep from scratching or further irritating the skin.
Never burn leaves in the fire ring or as toilet paper unless you are certain they are not of the poison ivy family.