Was the iPad in the sun? What was ambient temperature? Is it repeatable? Have you tried restoring to factory defaults? There may be some corruption that is now in the backup.
I now have the same problem. mine is 3 days old. yesterday it went into Restore mode & I had to rebuild. Lost an entire day of remote work. I did a full restore. reset all the logins & stuff lost. loaded some videos off Flip - used it for 4 hours after the restore. Went to wake it up, just now, - it's been off for 18 hours & got the temp warning. my house is at 67 degrees. it's in the apple case. I put a screen protector on it yesterday after the restore - still used it for the 4 hours yestday after doing that with no problem.
been using apple since 1984 - never had 2 major issues like this in 24 hours.
Any ideas? is this a lemon? Do I return to retailer or take to Apple store? I really need it work for my business.
You maynhave to trade it in, vut I think I'd try a few resets first. Take a look at the various options described in the Tips & Troubleshooting section of your manual, and also the reset options there in Settings.