Here is the Canon service advisory.
Most likely not your problem. Repair required. Balance repair quote against cost of new body from a reliable source like Keh.com
"Not sure how it would get overheated?"
That was just a thought not a diagnosis. As a concern some 70D cameras have experienced. SOmetimes electronic gear just fails. When you get your estimate, remember another used but working 70D is around $350 to $400 bucks. Also, keep in mind a 70D has got to be nearing end of service life. Perhaps an upgrade in camera is a good notion at this point.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
04/20/2023: New firmware version 1.4.1 is available for EOS R3
03/30/2023: New firmware updates are available.
2/07/2023: New product announcements!EOS R8 EOS R50RF-S55-210mm F5-7.1 IS STMRF24-50mm F4.5-6.3 IS STMRF15-30mm F4.5-6.3 IS STM