Nvidia has put out a global recall on Nvidia Shield Tablets sold between July 2014 and July 2015.
The batteries in some of the tablets could overheat and present a fire risk so Nvidia has pledged to replace any that could be affected. Not all tablets have the potentially faulty battery type, so you have to check your device in the settings before heading to the company's dedicated recall website to fill in the details.
You won't even need to send back the original tablet until after you have been sent the replacement. It will however be disabled remotely the moment you spark up the new one (although "spark up" might not be the best phrase we could have chosen, considering).
To check if your Shield Tablet is affected go to settings and then tap on "about tablet". Hit "status" and you should have a listing of the battery type. If it says "B01" next to "battery" you are okay and your tablet is not affected.
If, however, it says "Y01" you need to head to the dedicated Nvidia webite and request a replacement.
If you don't get either, you will more than likely need to install the latest software update for your device first.
Nvidia will replace the tablets like for like, so if you owned the LTE version, that's the one you'll get back.