It sure seems like some plants really don't want you hiking through their woods, but maybe your immune system is just overreacting.

The urushiol molecules in poison ivy have the ability to trigger a harmful immune response in most people because the immune system mistakenly labels them as a threat.

Ranger Steve helps you discover how to play it safe around Poison Oak (Toxicodendron diversilobum) while hiking the trails at Redwood National and State Parks.<b<br/>r/>

CREDIT: NPS