My Thinkpad x230 running coreboot bios and FreeBSD 12-ALPHA5. If I suspend the laptop while on ac power, then resume it, no problem at all. But when I do the following sequence
1) suspend laptop on AC power
2) Disconnect the AC adapter
3) Reconnect the AC adapter
4) Resume from S3
devd logs : WARNING: system temperature too high, shutting down soon!
and the laptop shuts down. It seems it is receiving _CRT or _HOT thermal events for some reason. The laptop is very cool and the fan is working correctly. I've tested Debian on a separate partition, and I never encountered the high temperature issue when resuming from suspend.