Many SMART attributes are all-or-nothing shots, or are "one defect fails". Sounds like the drive saw itself overheat once, and that was unacceptable to ever happen. (overheating can cause permanent damage, rendering it forever unreliable)
I generally consider any drive with a failing SMART status to be in need of immediate replacement. The checks I do on my drives go far beyond SMART, and in many cases I've caught a drive that was showing early signs of problems long in advance of SMART status toggling. (several of them toggled to FAIL while I was rescuing my data off to a replacement drive!) So although SMART can be an early warning, it's not as much advance notice as I'd like to see, and more often than not drives fail catastrophically before SMART toggles, so it's of limited use. But when it toggles, you should respect the warning you're being given.
If you send your mac in for warranty service, they will SWAP the hard drive, and you will have to specifically request (and pay for) data recovery to the new drive. So either make sure you get that, or that you have a backup yourself, if there's anything on the drive you need. (you said it was new tho so maybe not?)
