Do not touch or cut poison ivy. If you are particularly susceptible to poison ivy, don't cut vines.
Poison ivy is characterized by three somewhat glossy leaves but in the fall the leaves may change color and they may not be glossy.
Poison ivy often masquerades as part of the tree. Branches may look benign but they are really poison ivy. You can see that they originate at vines that cling to the tree.
Poison ivy vines usually cling to the tree with a mesh of little hair-like roots. The hairs are often orange.
Never cut vines that hug the tree.
We may miss a few invasives, but it's not worth the risk. Only cut free-hanging vines and even then, be sure that they are not poison ivy.
If you touch poison ivy, wash your hands thoroughly and/or shower.
If you touch poison ivy do not to rub your eyes or other parts of your body.
If your tools touch poison ivy, clean them thoroughly and be careful what they touch.
(photo credit - "Thatcher Drew - 501square.com"). Photos with no people in them are available for use with credit under creative commons license.