I found this wild caterpillar crawling around on my deck and induced it to crawl onto a leaf for a photo session. I believe those hairs sting, but did not give them a try. The orange highlights are wild, and sure look like warning colors.
-BugGuide account--Orgyia leucostigma.
This species does not have an entry in EOL under genus Orgyia, that I can find. As far as I know, this is the current, valid, name of the species.